Fabry-Pérot interferometer Updated +Created
Video 1.
Fabry Perot Interferometer by JFC UCL (2016)
Source. Description only, reasonable animations. Considers the case of two nearby beam splitters.
Video 2.
Fabry-Perot Introduction by Williams College Physics (2020)
Source.
Shows a working device. Confocal optical cavity, one of the mirrors scans back and forward moved by a piezoelectric motor, this is called a "scanning Fabry-Perot interferometer".
Does not produce an interference pattern, only an on/off blob, which is then fed into an oscilloscope for analysis. The oscilloscope shows both the mirror displacement (which is given by a voltage) and the light detector output.
Video 3.
Aligning a Scanning Fabry-Perot Interferometer by University of South Florida (2016)
Source. Very detailed, and shows of some nice equipment and techniques.
Faraday effect Updated +Created
@cirosantilli/_file/nodejs/sequelize/raw/nodejs/sequelize/raw/trigger_count.js Updated +Created
In this example we cache track the number of posts per user on a cache column.
Golden (wiki) Updated +Created
April 2024: merged with some fraud protection thing, is it sill a Wiki? Unclear, seem sto have lost that aspect: twitter.com/judegomila/status/1783028847983956430
techcrunch.com/2019/04/30/golden-launch/
To state the obvious: Wikipedia is an incredibly useful website, but Gomila pointed out that notable companies and technologies like SV Angel, Benchling, Lisk and Urbit don’t currently have entries. Part of the problem is what he called Wikipedia’s “arbitrary notability threshold,” where pages are deleted for not being notable enough. (This is also what happened years ago to the Wikipedia page about yours truly — which I swear I didn’t write myself.)
Exactly! Deletionism on Wikipedia is so sad, and especially for companies. In particular e.g. Ciro Santilli tried to create a page for PsiQuantum, and it got reverted... and now golden has one of the largest Google hits for it: golden.com/wiki/PsiQuantum-PBDGXRA
TODO how do they do moderation?
As of April 2024
Login is currently disabled.
Asked at: twitter.com/cirosantilli/status/1777250258235302233 Their last tweets were from August 2023, so maybe they just silently shutdown? Their name is too generic and hard to search for efficiently...
They do have knowledge graph built-in which is cool.
Good targets for amateur astronomy Updated +Created
Looking at most astronomical object through a telescope is boring because you only see a white ball or point every time. Such targets would likely only be interesting with spectroscopy analysis.
There are however some objects that you can see the structure of even with an amateur telescope, and that makes them very exciting.
Some good ones:
Magazine Updated +Created
China front Updated +Created
I've started rewatching The Water Margin, it is just so good. I'm taking some reasonable notes this time however, because due to Ciro Santilli's bad old event memory I'll forget the details again otherwise.
That type of rebellion symbology could also be useful against the Chinese government. It is interesting that Mao Zedong loved the novel.
Video 1.
Water Margin tribute to Chinese dissidents
. Source.
Chemical compound Updated +Created
The definition does not include homonuclear molecules which is a pain.
Exception to the Madelung energy ordering rule Updated +Created
The most notable exception is the borrowing of 3d-orbital electrons to 4s as in chromium, leading to a 3d5 4s1 configuration instead of the 3d4 4s2 we would have with the rule. TODO how is that observed observed experimentally?
Fiat currency Updated +Created
A useless piece of paper (or digital version of it) that you can pay taxes with :)
As opposed to:
Google Quantum AI Updated +Created
Google's quantum hardware/software effort.
The "AI" part is just prerequisite buzzword of the AI boom era for any project and completely bullshit.
According to job postings such as: archive.ph/wip/Fdgsv their center is in Goleta, California, near Santa Barbara. Though Google tends to promote it more as Santa Barbara, see e.g. Daniel's t-shirt at Video "Building a quantum computer with superconducting qubits by Daniel Sank (2019)".
Video 1.
Control of transmon qubits using a cryogenic CMOS integrated circuit (QuantumCasts) by Google (2020)
Source. Fantastic video, good photos of the Google Quantum AI setup!
Gordon Linoff Updated +Created
Infinitely many SQL answers.
As mentioned at Ciro Santilli's Stack Overflow contributions, he just answers every semi-duplicate immediatly as it is asked, and is therefore able to overcome the Stack Overflow maximum 200 daily reputation limit by far. E.g. in 2018, Gordon reached 135k (archive), thus almost double the 73k yearly limit due to the 200 daily limit, all of that with accepts.
This is in contrast to Ciro Santilli's contribution style which is to only answer questions as he needs the subject, or generally important questions that aroused his interest.
2014 Blog post describing his activity: blog.data-miners.com/2014/08/an-achievement-on-stack-overflow.html, key quote:
For a few months, I sporadically answered questions. Then, in the first week of May, my Mom's younger brother passed away. That meant lots of time hanging around family, planning the funeral, and the like. Answering questions on Stack Overflow turned out to be a good way to get away from things. So, I became more intent.
so that suggests his contributions also take a meditative value.
www.data-miners.com/linoff.htm mentions he's an SQL consultant that consulted for several big companies.
LinkedIn profile: www.linkedin.com/in/gordonlinoff/ says he now works at the New York Times.
2021 Reddit thread about him: www.reddit.com/r/programming/comments/puok1h/a_single_person_answered_76k_questions_about_sql/ mentions that by then he had:
answered 76k questions about SQL on StackOverflow. Averaging 22.8 answers per day, every day, for the past 8.6 years.
gothinkster/django-realworld-example-app Updated +Created
As of 2021, last updated 2016, and python 3.5 appears to be mandatory or else:
RuntimeError: __class__ not set defining 'AbstractBaseUser' as <class 'django.contrib.auth.base_user.AbstractBaseUser'>. Was __classcell__ propagated to type.__new__?
which apparently broke in 3.6: stackoverflow.com/questions/41343263/provide-classcell-example-for-python-3-6-metaclass and pyenv install fails on Ubuntu 20.10, so... fuck. Workarounds at:but am I in the mood considering that the ancient Django version would require an immediate port anyways? Repo is at Django 1.0, while newest is now already Django 3. The Rails one is broken for the same reason. Fuck 2.
Gradient Updated +Created
Takes a scalar field as input and produces a vector field.
Mnemonic: the gradient shows the direction in which the function increases fastest.
Think of a color gradient going from white to black from left to right.
Therefore, it has to:
  • take a scalar field as input. Otherwise, how do you decide which vector is larger than the other?
  • output a vector field that contains the direction in which the scalar increases fastest locally at each point. This has to give out vectors, since we are talking about directions
Gram-negative bacteria Updated +Created
Open source LLM Updated +Created
Cosmic microwave background anisotropy Updated +Created
There is a slight variation in temperature of CMB across the sky of the order of 200 microKelvin. It is small to the ~2.7 K average temperature, but it can be measured.
If the initial conditions of the Big Bang and the laws of physics were perfectly symmetric, then we could expect the universe to just be one perfectly uniform boring soup.
But instead some asymetry made all the fun weird things we see today happen eventually, like galaxies and life.
And the cosmic microwave background serves as a way for us to look back in time to the early conditions of the universe, as it was set in stone as soon as the universe became transparent to this light during recombination.
Or if you want to get poetic, it is the closest we can ever get to listening to the original word of God when he setup the initial conditions of the universe.
The ansiotropies of CMB is the ultimate astronomical compass we will ever have, as it is the thing with the least proper motion.
Course of the University of Cambridge Updated +Created

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