Path integral formulation Updated 2025-07-16
This one might actually be understandable! It is what Richard Feynman starts to explain at: Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979).
The difficulty is then proving that the total probability remains at 1, and maybe causality is hard too.
The path integral formulation can be seen as a generalization of the double-slit experiment to infinitely many slits.
Feynman first stared working it out for non-relativistic quantum mechanics, with the relativistic goal in mind, and only later on he attained the relativistic goal.
TODO why intuitively did he take that approach? Likely is makes it easier to add special relativity.
This approach more directly suggests the idea that quantum particles take all possible paths.
Renormalization Updated 2025-07-16
Graphomania Updated 2025-07-16
Magnetic dipole in an inhomogenous magnetic field Updated 2025-07-16
Is the MacOS kernel open source? Updated 2025-07-16
Organizationally unique identifier Updated 2025-07-16
Lysozyme structure resolution (1965) Updated 2025-07-16
With X-ray crystallography by David Chilton Phillips. The second protein to be resolved fter after myoglobin, and the first enzyme.
Published at: Structure of Hen Egg-White Lysozyme: A Three-dimensional Fourier Synthesis at 2 Å Resolution (1965). The work was done while at the Davy Faraday Research Laboratory of the Royal Institution.
Phillips also published a lower resolution (6angstrom) of the enzyme-inhibitor complexes at about the same time: Structure of Some Crystalline Lysozyme-Inhibitor Complexes Determined by X-Ray Analysis At 6 Å Resolution (1965). The point of doing this is that it points out the active site of the enzyme.
Aether theory Updated 2025-07-16
Coulomb gauge Updated 2025-07-16
Alternative to the Lorentz gauge, but less used in general as it is not as nice for relativity invariance.
Lorentz invariant Updated 2025-07-16
Last mile problem Updated 2025-07-16
The exact same problem appears over and over, e.g.:
- transportaion: the last mile of the trip when everyone leaves the train and goes to their different respective offices is the most expensive
- telecommunications: the last mile of wire linking local hubs to actual homes is the most expensive
- electrical grid: same as telecommunications
Ciro Santilli also identified knowledge version of this problem: the missing link between basic and advanced.
Existence of the matrix logarithm Updated 2025-07-16
en.wikipedia.org/wiki/Logarithm_of_a_matrix#Existence mentions it always exists for all invertible complex matrices. But the real condition is more complicated. Notable counter example: -1 cannot be reached by any real .
The Lie algebra exponential covering problem can be seen as a generalized version of this problem, because
- Lie algebra of is just the entire
- we can immediately exclude non-invertible matrices from being the result of the exponential, because has inverse , so we already know that non-invertible matrices are not reachable
Bert Hubert Updated 2025-07-16
Co-founder of PowerDNS, an open source dNS implementation.
Homepage: berthub.eu/ says:.
All stuff Ciro cares about too! Cool dude! In particular Ciro loved his quote of I should have loved biology.
All stuff Ciro cares about too! Cool dude! In particular Ciro loved his quote of I should have loved biology.
He's writing a fun-sounding book about molecular biology as of 2022: berthub.eu/dna-book. Appears to be closed source though. Ciro wonders if he really needs to sell the book for money after all those years though, rather than just publishing it online for free.
Looking at Bert just brings the Dutch Golden Age, and more in particular Antonie van Leeuwenhoek to mind. Epic.
How life is Digital by Bert Hubert (2021)
Source. Just a "boring" overview of the central dogma of molecular biology ;-) Eli Benderski Updated 2025-07-16
Homepage: eli.thegreenplace.net/
Also has many great contributions on Stack Overflow: stackoverflow.com/users/8206/eli-bendersky
As of 2016, Eli worked at Google (reference). TODO before that, I had found his earlier info previously but lost it.
Eli focuses mostly on compiler toolchains.
He also has some mathematics stuff, so cute: eli.thegreenplace.net/2015/change-of-basis-in-linear-algebra/
Fabrice Bellard Updated 2025-07-16
Creator of QEMU and FFmpeg, both of which Ciro Santilli deeply respects. And a bunch other random stuff.
What is shocking about Fabrice this is that both are insanely important software that Ciro Santilli really likes, and both seem to be completely unrelated subjects!
Google made billions on top of this dude:
- FFmpeg is the backend of YouTube
- QEMU is the default emulator for Android Studio as of 2019, which Android developers use by default under the hood to develop Android Apps on their desktop without the need for a real device.
At last but not least, Fabrice also studied in the same school that Ciro Santilli studied in France, École Polytechnique.
It is a shame that he keeps such a low profile, there are no videos of him on the web, and he declines interviews.
Another surprising fact is that Fabrice has not worked for the "Big Tech Companies" as far as can be publicly seen, but rather mostly on smaller companies that he co-founded: www.quora.com/Computer-Programmers/Computer-Programmers-Where-is-Fabrice-Bellard-employed
And he's also into some completely random projcts unsurprisingly:
- www.computerhistory.org/tdih/january/6/ Computer Scientist Fabrice Bellard Announces Computing Pi to Record Number of Digits
Bibliography:
- smartbear.com/de/blog/2011/fabrice-bellard-portrait-of-a-super-productive-pro/ contains a list of his projects as of 2011
Fabrice Bellard in 2007
. Source. At a restaurant with the author apparently. Plus Miguel De Icaza who was in Paris for some conference, which they all presumably attended.
Fabrice Bellard with light
. There are no in-focus images of Fabrice on the Internet. Linus Torvalds Updated 2025-07-16
Aaron Swartz Updated 2025-07-16
Aaron, Ciro Santilli will complete your quest to make eduction free. Just legally this time, with the and with the Creative Commons license you helped to create.
Ciro likes how The Internet's Own Boy (2014) explains how Aaron felt like high school was bullshit, and that he could learn whatever he wanted from books, which is one of Ciro's key feelings.
James Somers Updated 2025-07-16
Huge interest overlap with Ciro Santilli, e.g. he's into
- molecular biology in general: I should have loved biology by James Somers
- JCVI-syn3.0: www.newyorker.com/magazine/2022/03/07/a-journey-to-the-center-of-our-cells
- cryo-EM: www.newyorker.com/magazine/2022/03/07/a-journey-to-the-center-of-our-cells
- David Goodsell: www.newyorker.com/magazine/2022/03/07/a-journey-to-the-center-of-our-cells
- History of Google: www.newyorker.com/magazine/2018/12/10/the-friendship-that-made-google-huge
Sandy Maguire Updated 2025-07-16
Lots of similar ideologies to Ciro Santilli, love it:
- sandymaguire.me/blog/reaching-climbing/: don't be a pussyOne is also reminded of Gwern Branwen. Sandy is also into self-improvement stuff, so even more like Gwern. This is a point Ciro diverges on. Ciro works actively on self-worsening.
Last Friday was my final day at work. According to my facebook profile, I am now "happily retired." As of today, I don't plan to do another day of "traditional work" in my life. That's not to say that I'll be sitting idle playing tiddly winks. I want to build things, to dedicate my life to independent study, and to get really, really good with building communities. I don't have time for any of this "work" stuff that somehow pervades our entire culture, choking our inspiration and sapping our energy away from the things we'd rather be doing.
- he thinks university is useless:
- sandymaguire.me/blog/where-uni-fails/ Where University Fails (2018), mostly talking about backward design
- sandymaguire.me/blog/gatekept/ rejected from Imperial College PhD program due to grade being slightly too low for their stupid requirements, even though he had a referral already, and an amazing CV
- he likes jazz: sandymaguire.me/blog/too-smart/
Other interesting points:
- sandymaguire.me/blog/sandy-runback/ he changed his own name to Sandy because he didn't like it, he was born Alexander
- algebradriven.design/ closed source books though, ouch. At least they seem to have been made with leanpub though, could be worse.
Dan Dascalescu Updated 2025-07-16
This dude is interesting. Quite crazy type. It is hard to differentiate genius from mad.
Ciro Santilli bumps on his Stack Overflow from time to time: stackoverflow.com/users/1269037/dan-dascalescu.
There are unlisted articles, also show them or only show them.