Ciro Santilli @cirosantilli 40

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Counterintelligence Updated 2025-07-16

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Counter-Strike Updated 2025-07-16

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Counties of the United Kingdom Updated 2025-07-16

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There are few different versions. The most important as of 2020 are:

historic counties of England: these are more fixed, but useless for politics
administrative counties of England: these evolve with politics more

No one is capable of offering an official/more generalized (why can't Google Maps do this properly?) map than these people: wikishire.co.uk/map/#/centre=54.004,-4.500/zoom=7 So so be it.

Video 1.

English counties explained by Jay Foreman (2021)

Source.

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Countries of the United Kingdom Updated 2025-07-16

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Country in Europe Updated 2025-07-16

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Course of the University of Oxford Updated 2025-07-16

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Course actually means "degree", not just one specific "course":

The course outline is given in a "handbook", a one or more PDF files that contain what people will learn and other practicalities. There is a full list of handbooks at: www.ox.ac.uk/students/academic/guidance/undergraduate/handbooks, but many of them are closed. The system is so closed that even the fucking course list is closed, e.g. all links at: www2.physics.ox.ac.uk/students/undergraduates are closed. Insane.

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Coursera Updated 2025-07-16

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Some courses at least allow you to see material for free, e.g.: www.coursera.org/learn/quantum-optics-single-photon/lecture/UYjLu/1-1-canonical-quantization. Lots of video focus as usual for MOOCs.

Some are paywalled: www.coursera.org/learn/theory-of-angular-momentum?specialization=quantum-mechanics-for-engineers

It is extremely hard to find the course materials without enrolling, even if enrolling for free! By trying to make money, they make their website shit.

The comment section does have a lot of activity: www.coursera.org/learn/statistical-mechanics/discussions/weeks/2! Nice. And works like a proper issue tracker. But it is also very hidden.

November 2023 topics:

quantum field theory: no
condensed matter: 1 by Rahul Nandkishore from Colorado Boulder: www.coursera.org/specializations/the-physics-of-emergence-introduction-to-condensed-matter

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Courtship Updated 2025-07-16

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Covariance Updated 2025-07-16

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Generally means that he form of the equation

f (x)

does not change if we transform

x

This is generally what we want from the laws of physics.

E.g. a Galilean transformation generally changes the exact values of coordinates, but not the form of the laws of physics themselves.

Lorentz covariance is the main context under which the word "covariant" appears, because we really don't want the form of the equations to change under Lorentz transforms, and "covariance" is often used as a synonym of "Lorentz covariance".

TODO some sources distinguish "invariant" from "covariant": invariant vs covariant.

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Covering space Updated 2025-07-16

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Basically it is a larger space such that there exists a surjection from the large space onto the smaller space, while still being compatible with the topology of the small space.

We can characterize the cover by how injective the function is. E.g. if two elements of the large space map to each element of the small space, then we have a double cover and so on.

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C++ memory model Updated 2025-07-16

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stackoverflow.com/questions/6319146/c11-introduced-a-standardized-memory-model-what-does-it-mean-and-how-is-it-g

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C POSIX library Updated 2025-07-16

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Quick overview at stackoverflow.com/questions/1780599/what-is-the-meaning-of-posix/31865755#31865755

Exmples under c/posix:

c/posix/signal_return.c: stackoverflow.com/questions/37063212/where-does-signal-handler-return-back-to
c/posix/inet/pton.c: inet_pton demo. Adapted from man inet_pton on Ubuntu 23.04. Usage:
```
./pton.out 192.187.1.42
```
Output:
```
0xc0bb012a
```
So we see that the strings was converted to an integer, e.g.:
- 0xc0 = 192
- 0xbb = 187
- 0x01 = 1
- 0x2a = 42
See also: stackoverflow.com/questions/1680622/ip-address-to-integer-c/76520978#76520978
c/posix/inet/ntop.c: inet_ntop demo. Adapted from man inet_pton on Ubuntu 23.04. Usage:
```
./ntop.out 0x01021AA0
```
Output:
```
./ntop.out 0x01021AA0
```

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DeepMind project Updated 2025-07-16

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Create a test user in PostgreSQL Updated 2025-07-16

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In order to create a test user with password instead of peer authentication, let's create test user:

createuser -P user0
createdb user0

-P makes it prompt for the users password.

Alternatively, to create the password non-interactively stackoverflow.com/questions/42419559/postgres-createuser-with-password-from-terminal:

psql -c "create role NewRole with login password 'secret'"

Can't find a way using the createuser helper.

We can then login with that password with:

psql -U user0 -h localhost

which asks for the password we've just set, because the -h option turns off peer authentication, and turns off password authentication.

The password can be given non-interactively as shown at stackoverflow.com/questions/6405127/how-do-i-specify-a-password-to-psql-non-interactively with the PGPASSWORD environment variable:

PGPASSWORD=a psql -U user0 -h localhost

Now let's create a test database which user0 can access with an existing superuser account:

createdb user0db0
psql -c 'GRANT ALL PRIVILEGES ON DATABASE user0db0 TO user0'

We can check this permission with:

psql -c '\l'

which now contains:

                                  List of databases
   Name    |  Owner   | Encoding |   Collate   |    Ctype    |   Access privileges
-----------+----------+----------+-------------+-------------+-----------------------
 user0db0  | ciro     | UTF8     | en_GB.UTF-8 | en_GB.UTF-8 | =Tc/ciro             +
           |          |          |             |             | ciro=CTc/ciro        +
           |          |          |             |             | user0=CTc/ciro

The permission letters are explained at:

user0 can now do the usual table operations on that table:

PGPASSWORD=a psql -U user0 -h localhost user0db0 -c 'CREATE TABLE table0 (int0 INT, char0 CHAR(16));'
PGPASSWORD=a psql -U user0 -h localhost user0db0 -c "INSERT INTO table0 (int0, char0) VALUES (2, 'two'), (3, 'three'), (5, 'five'), (7, 'seven');"
PGPASSWORD=a psql -U user0 -h localhost user0db0 -c 'SELECT * FROM table0;'

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Creator of Archive.today Updated 2025-07-16

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