web.archive.org/web/20181119214326/https://www.bipm.org/utils/common/pdf/CGPM-2018/26th-CGPM-Resolutions.pdf gives it in raw:The breakdown is:
- the unperturbed ground state hyperfine transition frequency of the caesium-133 atom is 9 192 631 770 Hz
- the speed of light in vacuum c is 299 792 458 m/s
- the Planck constant h is 6.626 070 15 × J s
- the elementary charge e is 1.602 176 634 × C
- the Boltzmann constant k is 1.380 649 × J/K
- the Avogadro constant NA is 6.022 140 76 × mol
- the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, is 683 lm/W,
- actually use some physical constant:
the unperturbed ground state hyperfine transition frequency of the caesium-133 atom is 9 192 631 770 Hz
Defines the second in terms of caesium-133 experiments. The beauty of this definition is that we only have to count an integer number of discrete events, which is what allows us to make things precise.the speed of light in vacuum c is 299 792 458 m/s
Defines the meter in terms of speed of light experiments. We already had the second from the previous definition.the Planck constant h is 6.626 070 15 × J s
Defines the kilogram in terms of the Planck constant.the elementary charge e is 1.602 176 634 × C
Defines the Coulomb in terms of the electron charge.
- arbitrary definitions based on the above just to match historical values as well as possible:
the Boltzmann constant k is 1.380 649 × J/K
Arbitrarily defines temperature from previously defined energy (J) to match historical values.the Avogadro constant NA is 6.022 140 76 × mol
the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, is 683 lm/W
Arbitrarily defines the Candela in terms of previous values to match historical records. The most useless unit comes last as you'd expect.
Resonance is a really cool thing.
Examples:
- mechanical resonance, notably:
- pipe instruments
- electronic oscillators, notably:
- LC oscillator, and notably the lossy version RLC circuit
Perhaps a key insight of resonance is that the reonant any lossy system tends to look like the resonance frequency quite quickly even if the initial condition is not the resonant condition itself, because everything that is not the resonant frequency interferes destructively and becomes noise. Some examples of that:
- striking a bell or drum can be modelled by applying an impuse to the system
- playing a pipe instrument comes down to blowing a piece that vibrates randomly, and then leads the pipe to vibrate mostly in the resonant frequency. Likely the same applies to bowed string instruments, the bow must be creating a random vibration.
- playing a plucked string instrument comes down to initializing the system to an triangular wave form and then letting it evolve. TODO find a simulation of that!
Another cool aspect of resonance is that it was kind of the motivation for de Broglie hypothesis, as de Broglie was kind of thinking that electroncs might show discrete jumps on atomic spectra because of constructive interference.
dumps.wikimedia.org/enwiki/latest/enwiki-latest-category.sql.gz contains a list of categories. It only contains the categories and some counts, but it doesn't contain the subcategories and pages under each category, so it is a bit pointless.
The schema is listed at: www.mediawiki.org/wiki/Manual:Category_table
The SQL first defines the table:followed by a few humongous inserts:which we can see at: en.wikipedia.org/wiki/Category:Computer_storage_devices
CREATE TABLE `category` (
`cat_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`cat_title` varbinary(255) NOT NULL DEFAULT '',
`cat_pages` int(11) NOT NULL DEFAULT 0,
`cat_subcats` int(11) NOT NULL DEFAULT 0,
`cat_files` int(11) NOT NULL DEFAULT 0,
PRIMARY KEY (`cat_id`),
UNIQUE KEY `cat_title` (`cat_title`),
KEY `cat_pages` (`cat_pages`)
) ENGINE=InnoDB AUTO_INCREMENT=249228235 DEFAULT CHARSET=binary ROW_FORMAT=COMPRESSED;
INSERT INTO `category` VALUES (2,'Unprintworthy_redirects',1597224,20,0),(3,'Computer_storage_devices',88,11,0)
Se see that en.wikipedia.org/wiki/Category:Computer_storage_devices_by_companyso it contains only categories.
- en.wikipedia.org/wiki/Category:Computer_storage_devices is a subcategory of that category and it appears in that file.
- en.wikipedia.org/wiki/Acronis_Secure_Zone is a page of the category, and it does not appear
We can check this with:and it shows:There doesn't seem to be any interlink between the categories, only page and subcategory counts therefore.
sed -s 's/),/\n/g' enwiki-latest-category.sql | grep Computer_storage_devices
(3,'Computer_storage_devices',88,11,0
(521773,'Computer_storage_devices_by_company',6,6,0
As of 2022, this tends to be the more "default" when you talk about a quantum computer.
But there are some serious analog quantum computer contestants in the field as well.
Precursor organization to the Oak Ridge National Laboratory, name that it took in January 1948.
Produced the enriched uranium used for Little Boy, located in the area/predecessor of Oak Ridge National Laboratory.
This ISA basically completely dominated the smartphone market of the 2010s and beyond, but it started appearing in other areas as the end of Moore's law made it more economical logical for large companies to start developing their own semiconductor, e.g. Google custom silicon, Amazon custom silicon.
It is exciting to see ARM entering the server, desktop and supercomputer market circa 2020, beyond its dominant mobile position and roots.
Ciro Santilli likes to see the underdogs rise, and bite off dominant ones.
The excitement also applies to RISC-V possibly over ARM mobile market one day conversely however.
Basically, as long as were a huge company seeking to develop a CPU and able to control your own ecosystem independently of Windows' desktop domination (held by the need for backward compatibility with a billion end user programs), ARM would be a possibility on your mind.
- in 2020, the Fugaku supercomputer, which uses an ARM-based Fujitsu designed chip, because the number 1 fastest supercomputer in TOP500: www.top500.org/lists/top500/2021/11/It was later beaten by another x86 supercomputer www.top500.org/lists/top500/2022/06/, but the message was clearly heard.
- 2012 hackaday.com/2012/07/09/pedal-powered-32-core-arm-linux-server/ pedal-powered 32-core Arm Linux server. A publicity stunt, but still, cool.
- AWS Graviton
It is fucking annoying!
- www.reddit.com/r/ProtonMail/comments/pn21dn/have_to_log_in_every_time_i_restart_the_browser/
- www.reddit.com/r/ProtonMail/comments/6qwm9w/automatic_login_to_protonmail_from_browser/
- protonmail.uservoice.com/forums/945460-general-ideas/suggestions/48228635-mail-proton-me-should-automatically-login-to-last
Not just on browser close. Whenever Ciro Santilli pastes proton.me/ on the browser bar and click enter. Chromium 123.
More precisely: pasting mail.proton.me on the browser bar redirects to account.proton.me/switch each time. From there, selecting different accounts leads to different mail.proton.me/u/<UID>/inbox, e.g. mail.proton.me/u/41/inbox is my main one. If I paste mail.proton.me/u/41/inbox on the browser, then it works directly.
How many stupid bugs. How many stupid bugs do we need to face???
- this fucking train-wreck cannot come up with a unified documented way of specifying dependencies:So basically
- stackoverflow.com/questions/14399534/reference-requirements-txt-for-the-install-requires-kwarg-in-setuptools-setup-py
- stackoverflow.com/questions/26900328/install-dependencies-from-setup-py
- stackoverflow.com/questions/30797124/how-to-use-setup-py-to-install-dependencies-only/63743115
- stackoverflow.com/questions/6947988/when-to-use-pip-requirements-file-versus-install-requires-in-setup-py
requirements.txt
is thepackage-lock.json
. But how to generate it cleanly? You would need to create a virtualenv? pip search
was disabled in 2020: stackoverflow.com/questions/17373473/how-do-i-search-for-an-available-python-package-using-pip. WTF. If server load is a problem, just create a token system! It is hard to understand how such a popular language can't rais enough money to keep such simple server functionality running.
It is true, something Ciro Santilli often things about. One likely reason is that the world is broken and most cyclist are speed maniacs willing to put the time in. Unlike Dutch people where everyone cycles.
This section is about wikis that are hosted on a blockchain of some sort.
Linear map of two variables.
More formally, given 3 vector spaces X, Y, Z over a single field, a bilinear map is a function from:that is linear on the first two arguments from X and Y, i.e.:Note that the definition only makes sense if all three vector spaces are over the same field, because linearity can mix up each of them.
The most important example by far is the dot product from , which is more specifically also a symmetric bilinear form.
TODO vs Phylogenetic tree? www.visiblebody.com/blog/phylogenetic-trees-cladograms-and-how-to-read-them:
Cladograms and phylogenetic trees are functionally very similar, but they show different things. Cladograms do not indicate time or the amount of difference between groups, whereas phylogenetic trees often indicate time spans between branching points.
TODO this would give a better motivation for the Mathieu group
Ciro Santilli wants to rule this with OurBigBook.com.
A hot hot place.
This is not a truly "fundamental" constant of nature like say the speed of light or the Planck constant.
Rather, it is just a definition of our Kelvin temperature scale, linking average microscopic energy to our macroscopic temperature scale.
The way to think about that link is, at 1 Kelvin, each particle has average energy:per degree of freedom.
For an ideal monatomic gas, say helium, there are 3 degrees of freedom. so each helium atom has average energy:
If we have 2 atoms at 1 K, they will have average energy , and so on.
Another conclusion is that this defines temperature as being proportional to the total energy. E.g. if we had 1 helium atom at 2 K then we would have about energy, 3 K and so on.
This energy is of course just an average: some particles have more, and others less, following the Maxwell-Boltzmann distribution.
For a critique/history of this insanity, see also: Section "Colleges of the University of Oxford".
There are unlisted articles, also show them or only show them.