Organ (anatomy) Updated +Created
Organelle Updated +Created
Organization developing photonic quantum computer Updated +Created
Origins of Precision by Machine Thinking (2017) Updated +Created
Great overview of the earlier history of unit standardization.
Gives particular emphasis to the invention of gauge blocks.
Internet Archive Open Library Updated +Created
You can borrow online books from them for a few hours/days: help.archive.org/hc/en-us/articles/360016554912-Borrowing-From-The-Lending-Library This is the most amazing thing ever made!!! You can even link to specific pages, e.g. archive.org/details/supermenstory00murr/page/80/mode/2up
They seem to a have a separate URL with the same content as well for some reason: openlibrary.org/, classic messy Internet Archive style.
Bastards are suing them www.theverge.com/2020/6/1/21277036/internet-archive-publishers-lawsuit-open-library-ebook-lending: Hachette, Penguin Random House, Wiley, and HarperCollins
It is quite hard to decide if an upload is from the official legal lending library, or just some illegal upload, e.g.:so the URLs are basically the same style. Some legality indicators:
Invariant vs covariant Updated +Created
Some sources distinguish "invariant" from "covariant" such that under some transformation (typically Lie group):
  • invariant: the value of does not change if we transform
  • covariant: the form of the equation does not change if we transform .
TODO examples.
OurBigBook.com Updated +Created
The website is the reference instance of OurBigBook Web, which is part of the OurBigBook Project, the other main part of the project are software that users can run locally to publish their content such as the OurBigBook CLI.
This page contains further information about the project's rationale, motivation and planning.
Video 1.
Intro to the OurBigBook Project
. Source.
Figure 1.
The topics feature allows you to find the best version of a subject written by other users user
. Live demo: derivative.
OurBigBook.com / Learning management systems Updated +Created
This website basically aims to be a learning management system, allowing in particular a teacher to focus his help on students that he is legally obliged to help due to their job. But it will have the following unusual characteristics in current LMS solutions:
  • public first, to allow reuse across universities, rather than paywalled as is the case for most top universities
  • students can create material just like teachers, both are on equal footing. Students/teachers will see an indicator "this is your teacher"/"this is your student for this/past semester", but that is the only difference between their interfaces.
Inverse AC Josephson effect Updated +Created
If you shine microwave radiation on a Josephson junction, it produces a fixed average voltage that depends only on the frequency of the microwave. TODO how is that done more precisely? How to you produce and inject microwaves into the thing?
It acts therefore as a perfect frequency to voltage converter.
The Wiki page gives the formula: en.wikipedia.org/wiki/Josephson_effect#The_inverse_AC_Josephson_effect You get several sinusoidal harmonics, so the output is not a perfect sine. But the infinite sum of the harmonics has a fixed average voltage value.
And en.wikipedia.org/wiki/Josephson_voltage_standard#Josephson_effect mentions that the effect is independent of the junction material, physical dimension or temperature.
All of the above, compounded with the fact that we are able to generate microwaves with extremely precise frequency with an atomic clock, makes this phenomenon perfect as a Volt standard, the Josephson voltage standard.
TODO understand how/why it works better.
Is fog computing more efficient than cloud computing? Updated +Created
Advantages of fog: there is only one, reusing hardware that would be otherwise idle.
Disadvantages:
  • in cloud, you can put your datacenter on the location with the cheapest possible power. On fog you can't.
  • on fog there is some waste due to network communication.
  • you will likely optimize code less well because you might be targeting a wide array of different types of hardware, so more power (and time) wastage. Furthermore, some of the hardware used will not not be optimal for the task, e.g. CPU instead of GPU.
All of this makes Ciro Santilli doubtful if it wouldn't be more efficient for volunteers simply to donate money rather than inefficient power usage.
Bibliography:
DNS database Updated +Created
A "DNS database" is a database that stores DNS records, notably A-records, which IP a domains is hosted at.
For currently live domains, domain to IP can of course be easily determined on the fly by just resolving the domain like the browser does, e.g.
cirosantilli.com
What is hard however is:
  • the other way around is harder however: given an IP, list all domains that it hosts. This is known as "reverse IP" searching.
  • historic data, i.e. what was the IP for a given domain at a given date and vice versa
As of 2023, working with DNS data is just going through a mish-mash of closed datasets/expensive APIs.
Some links of interest:
Don't be a pussy Updated +Created
!!! Survivorship bias alert !!!
quoteinvestigator.com/2018/05/07/overcome/
If you want to do something, but you are afraid to do it, then that is likely what you should do.
quoteinvestigator.com/2013/11/08/not-bend/
Don't bend; don't water it down; don't try to make it logical; don't edit your own soul according to the fashion. Rather, follow your most intense obsessions mercilessly.
www.goodreads.com/quotes/50458-whatever-you-re-meant-to-do-do-it-now-the-conditions Doris Lessing:
Whatever you're meant to do, do it now. The conditions are always impossible.
For example, when Ciro Santilli was deciding what to do in university, he wanted mostly to do pure physics.
But because he was afraid he was going to die poor and unemployed because of that, he picked engineering instead.
That was a mistake.
His family was not even poor. He was young and did not have a family to support. His father even told him: "do whatever the fuck you want, we support your decision".
But he was a coward.
It was also in part because a physicist uncle which he respected suggested that as an engineer Ciro might be able to make useful contributions to tooling required by physics. When Roberto Salmeron died in 2020, Ciro's friends shared this 2013 video interview with the late professor, where he explains he first went to the University of São Paulo to study engineering (like Ciro), but then fell for his passion for physics (like Ciro?), his first task being to build a Geiger counter, thus explaining the likely origin of the uncle's theory. But who knows, maybe he was right. Maybe Ciro's OurBigBook.com will become huge and help a lot of people, and it might not have had Ciro not done engineering and learnt programming. Destiny operates in weird ways sometimes.
Furthermore, while in University, Ciro learnt about the molecular Sciences Course of the University of São Paulo, a fantastic sounding full time course that any student could transfer to called that teaches various natural sciences topics which Ciro loves (Mathematics, Physics, Chemistry, Biology) and which students from the entire university can apply to transfer to only after joining the university, with the guarantee that they can go back to their original courses if they didn't adapt to the new course.
But did Ciro do it? Nope, he remained an even larger coward.
Had he studied more sciences, he might have been happier, and might have had greater achievements later in life, in particular when he went to École Polytechnique.
Maybe not, but now this doubt will never leave his mind until the final day.
Similar thoughts crossed his mind when he started his campaign for freedom of speech in China, but this time he had learnt the lesson, and went for it, and it felt very good.
If you have a day job, but also have a dream, and want to keep the day job for a reason, try to reserve the time of the day that your brain works best before or after work for your dream: do one cool thing every day.
Companies can help you grow because you see real problems from within them, but their end goal is to consume you as much as possible. Don't let that happen. Invest part of what you gain, in yourself. www.outsideonline.com/outdoor-adventure/paradox-going-outside/ The Paradox of Going Outside by James Somers (2012) puts it incredibly well:
I work, for instance, as a Web developer. It's a very good job. Our office is a block south of Union Square, a 12-minute commute from my apartment. We're served breakfast every morning. Our kitchen is stocked with "provisions" of organic beef jerky, coconut water, craft beers, chips, and two restaurant-class espresso machines. We have two ping pong tables and buckets of 3-star ping pong balls. (A new office manager bought "1-stars" once and some of the guys protested by crushing them.) We work on 4-cored Apple Mac computers with dual monitors. We have an unmolested hour for lunch, 10-minute breaks in the morning and afternoon, and a "do not disturb" policy past the working hours. We even have a specific email address where employees can ask for free things: genuine maple syrup, hot chocolate, a $900 chair, a new keyboard. Most of the programmers make six figures, and many of those have only three or four years of experience.
It's impossible to say so without sounding like the spokesperson for Entitlement itself but working there is still sort of soul-crushing. It's soul-crushing in the way that any job that doesn't command your full passionate attention must be. What happens is that I will be in my chair in the early afternoon and I will accidentally step out of myself and all I'll see is time passing, nine-hour parcels of healthy consciousness forever being packed away as the user experience of clerical workers or consumers or whoever gets marginally better; and I'll end up thinking that this enterprise of mine is not so much creative but bureaucratic, that what I've gotten good at is reading the instruction manuals of other people, finding my way around their insignificant warrens. And in those moments the whole business will seem to me like kind of a tragic waste.
Other quotes:
Don't be a pussy. Be a Based God
Figure 1.
Dilbert "A small brain irrationally puts more weight on a small loss than on a huge opportunity" cartoon (2000)
Source.
Figure 2.
Jake Likes Onions "Slowly" cartoon
. Source. This is what trying to reach a dream part time feels like. The cartoon reads: "The tiger pursues its prey. Slowly. The human pursues its life goals. Slowly. Very slowly.".
Video 1.
Excerpt from the documentary film "Steve Jobs: Secrets of Life" (1994)
Source.
When you grow up you tend to get told that the world is the way it is and your life is just to live your life inside the world. Try not to bash into the walls too much. Try to have a nice family life, have fun, save a little money. That's a very limited life. Life can be much broader once you discover one simple fact: Everything around you that you call life was made up by people that were no smarter than you. And you can change it, you can influence it... Once you learn that, you'll never be the same again.
Of course, survivorship bias alert!
Video 2.
What Would You Do If Money Were No Object by Alan Watts
. Source. Sample transcription: genius.com/Alan-watts-what-if-money-was-no-object-annotated:
What do you desire? What makes you itch? What sort of a situation would you like?
Let's suppose, I do this often in vocational guidance of students, they come to me and say, well, "we're getting out of college and we have the faintest idea what we want to do". So I always ask the question, "what would you like to do if money were no object? How would you really enjoy spending your life?"
Well, it's so amazing as a result of our kind of educational system, crowds of students say well, we'd like to be painters, we'd like to be poets, we'd like to be writers, but as everybody knows you can't earn any money that way. Or another person says well, I'd like to live an out-of-doors life and ride horses. I said you want to teach in a riding school?
Let's go through with it. What do you want to do? When we finally got down to something, which the individual says he really wants to do, I will say to him, you do that and forget the money, because, if you say that getting the money is the most important thing, you will spend your life completely wasting your time. You'll be doing things you don't like doing in order to go on living, that is to go on doing things you don't like doing, which is stupid. Better to have a short life that is full of what you like doing than a long life spent in a miserable way.
And after all, if you do really like what you're doing, it doesn't matter what it is, you can eventually turn it - you could eventually become a master of it. It's the only way to become a master of something, to be really with it. And then you'll be able to get a good fee for whatever it is. So don't worry too much. That's everybody is - somebody is interested in everything, anything you can be interested in, you will find others will.
But it's absolutely stupid to spend your time doing things you don't like, in order to go on spending things you don't like, doing things you don't like and to teach our children to follow in the same track. See what we are doing, is we're bringing up children and educating to live the same sort of lives we are living. In order that they may justify themselves and find satisfaction in life by bringing up their children to bring up their children to do the same thing, so it's all retch and no vomit. It never gets there. And so, therefore, it's so important to consider this question: What do I desire?
Video 3.
Keep Chargin' from a Show of Hands by Victor Wooten (1996)
Source.
That's the way I live my life, I give it my all. I think that a person should really make up his mind what he wants to do, and when did made up, he cannot fail at it. The basic rule to sucess I think, is when the going gets tough, that is a positive signal to keep chargin'.
Closely echoes Video 2. "What Would You Do If Money Were No Object by Alan Watts". Survivorship bias? Maybe. Beautiful? Unquestionably. So glad he was allowed to upload it officially to YouTube.
Video 4.
Your Life is Your life by Charles Bukowski
. Source.
Charles Bukowski is one of the most hardcore don't be a pussy people ever. It's almost scary. Far beyond Ciro level.
thebestamericanpoetry.typepad.com/the_best_american_poetry/2008/11/the-laughing-he.html
your life is your life
don't let it be clubbed into dank submission.
be on the watch.
there are ways out.
there is light somewhere.
it may not be much light but
it beats the darkness.
be on the watch.
the gods will offer you chances.
know them.
take them.
you can't beat death but
you can beat death in life, sometimes.
and the more often you learn to do it,
the more light there will be.
your life is your life.
know it while you have it.
you are marvelous
the Gods wait to delight
in you.
www.goodreads.com/quotes/39207-if-you-re-going-to-try-go-all-the-way-otherwise
If you're going to try, go all the way. Otherwise, don't even start. This could mean losing girlfriends, wives, relatives and maybe even your mind. It could mean not eating for three or four days. It could mean freezing on a park bench. It could mean jail. It could mean derision. It could mean mockery--isolation. Isolation is the gift. All the others are a test of your endurance, of how much you really want to do it. And, you'll do it, despite rejection and the worst odds. And it will be better than anything else you can imagine. If you're going to try, go all the way. There is no other feeling like that. You will be alone with the Gods, and the nights will flame with fire. You will ride life straight to perfect laughter. It's the only good fight there is.
I have one of two choices - stay in the post office and go crazy... or stay out here and play at writer and starve. I have decided to starve.
Figure 3.
Bukowski kissing his typewriter.
Like Ciro Santilli and his computer!
Video 5.
All adults are bored scene from an Edward Teller, An Early Time
. Source.
Up to the time that I met Klug ([a mathematiciam]), I was sure that all grown ups were people to be pitied. They had to work, they were tired, they were bored with what they were doing. I heard both my parents often complain. Klug was the first man whom I met who most obviously enoyed what he was doing.
But to be fair, being a fucking "genius" might be a requirement to escape that fate!
Figure 4.
Modern Sisyphus by Sephko
. Source.
Video 6.
"I just stopped thinking" scene from Malcolm in the Middle S05E21 "Reese Joins The Army"
. Source. Working in most big companies can feel like this sometimes. We need stronger AI (AGI?) to help wipe out this boredom. A anti-AGI blues moment for you.
Figure 5.
Do epic shit meme
. Source.
Do epic shit
Unless you are too tired, or it costs too much money, in which case, Do affordable shit, and make time for naps
Dot product Updated +Created
The definition of the "dot product" of a general space varies quite a lot with different contexts.
Most definitions tend to be bilinear forms.
We use the unqualified generally refers to the dot product of Real coordinate spaces, which is a positive definite symmetric bilinear form. Other important examples include:
The rest of this section is about the case.
The positive definite part of the definition likely comes in because we are so familiar with metric spaces, which requires a positive norm in the norm induced by an inner product.
The default Euclidean space definition, we use the matrix representation of a symmetric bilinear form as the identity matrix, e.g. in :
so that:
Dots in Gmail address Updated +Created
This allows you to create multiple non-anonymous accounts on any website that doesn't account for it, as this is not part of the email protocols in general.
Download all Wikipedia categories Updated +Created
Let's observe them in MySQL:
mysql enwiki -e "select page_id, page_namespace, page_title, page_is_redirect from page where page_namespace in (0, 14) and page_title in ('Computer_storage_devices', 'Computer_data_storage')"
outputs:
+----------+----------------+--------------------------+------------------+
| page_id  | page_namespace | page_title               | page_is_redirect |
+----------+----------------+--------------------------+------------------+
|     5300 |              0 | Computer_data_storage    |                0 |
| 42371130 |              0 | Computer_storage_devices |                1 |
|   711721 |             14 | Computer_data_storage    |                0 |
|   895945 |             14 | Computer_storage_devices |                0 |
+----------+----------------+--------------------------+------------------+
mysql enwiki -e "select cl_from, cl_to from categorylinks where cl_from in (5300, 711721, 895945, 42371130)"
gives:
+----------+-----------------------------------------------------------------------+
| cl_from  | cl_to                                                                 |
+----------+-----------------------------------------------------------------------+
|     5300 | All_articles_containing_potentially_dated_statements                  |
|     5300 | Articles_containing_potentially_dated_statements_from_2009            |
|     5300 | Articles_containing_potentially_dated_statements_from_2011            |
|     5300 | Articles_with_GND_identifiers                                         |
|     5300 | Articles_with_NKC_identifiers                                         |
|     5300 | Articles_with_short_description                                       |
|     5300 | Computer_architecture                                                 |
|     5300 | Computer_data_storage                                                 |
|     5300 | Short_description_matches_Wikidata                                    |
|     5300 | Use_dmy_dates_from_June_2020                                          |
|     5300 | Wikipedia_articles_incorporating_text_from_the_Federal_Standard_1037C |
|   711721 | Computer_architecture                                                 |
|   711721 | Computer_data                                                         |
|   711721 | Computer_hardware_by_type                                             |
|   711721 | Data_storage                                                          |
|   895945 | Computer_data_storage                                                 |
|   895945 | Computer_peripherals                                                  |
|   895945 | Recording_devices                                                     |
| 42371130 | Redirects_from_alternative_names                                      |
+----------+-----------------------------------------------------------------------+
So we see that cl_from encodes the parent categories:
So to find all articls and categories under a given category title, say en.wikipedia.org/wiki/Category:Mathematics we can run:
mariadb enwiki -e "select cl_from, cl_to, page_namespace, page_title from categorylinks inner join page on page_namespace in (0, 14) and cl_from = page_id and cl_to = 'Mathematics'"

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