Ciro Santilli (@cirosantilli) - Newly followed articles

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.

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Lysozyme structure resolution (1965) by

Ciro Santilli 35  Updated 2025-04-18  +Created 1970-01-01

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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 (6 angstrom) 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.

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Existence of the matrix logarithm by

Ciro Santilli 35  Updated 2025-04-18  +Created 1970-01-01

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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

e^{t k}

.

The Lie algebra exponential covering problem can be seen as a generalized version of this problem, because

Lie algebra of $G L (n)$ is just the entire $M_{n}$
we can immediately exclude non-invertible matrices from being the result of the exponential, because $e^{tM}$ has inverse $e^{- tM}$ , so we already know that non-invertible matrices are not reachable

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Sandy Maguire by

Ciro Santilli 35  Updated 2025-04-18  +Created 1970-01-01

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Lots of similar ideologies to Ciro Santilli, love it:

sandymaguire.me/about/:
- he's an idealist
I might best be described somewhere between independent researcher and voluntarily-unemployed bum. At the ripe old age of 27 I decided to quit my highly-lucrative engineering job and decide to focus more on living than on grinding for the man. It's what you might call a work in progress.
sandymaguire.me/blog/reaching-climbing/: don't be a pussy
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.
One 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.
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.

He's a Haskell person.

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Heroin by