Ciro Santilli @cirosantilli 37

Firstly, in 2012, while he was at École Polytechnique, Ciro Santilli was introduced to LaTeX (thank God for French mathematical obsession), and his mind was blown:he though. Why isn't everyone doing that!

One particular event stood out: Ciro made a small change to his teacher's course material, who blessed be him (dude's a legend, Ciro just noticed he has some Chinese publications with another French dude, e.g. www.amazon.co.uk/高效算法-应试与提高必修128例-克里斯托弗-Christoph-Durr/dp/B078SJQPVK "High-efficiency algorithm competitions 128 examples", did he write it the Chinese himself?? Must be of course to complement the notoriously low French professor salaries), made it available, and then Ciro gave him back the .tex file. Ciro was just a bit worried about how the teacher would be able to tell what he had changed in the file to validate the change. The teacher just said of course, "no problem, I'll just use diff". Ciro had never heard of diff. Let alone Git of course, though yes, this was a bit early in Git's history version control systems had been around since forever of course. This was 2011 or 2012, about 4 or 5 years into a superior education curricula with various courses involving computers, some requiring quite a lot of "fill these empty functions" style programming. Education is a joke. Anyways, this was a prelude to exactly what Ciro wanted to do in OurBigBook.com. This might have been the one actually: webia.lip6.fr/~durrc/Iut/Notes580.pdf

Not long afterwards, Ciro started playing with Linux. Until then, Ciro had had some contacts with the mysterious operating system at university, and was a bit puzzled what the point of it was! He clearly remembers:University should be forced to use only open source software and hardware in undergrad teaching courses by law BTW.

Then came an Ubuntu live disk on his own machine, and finally a measly 40GB dual book partition in a Microsoft Windows machine on a laptop. At first, it took a lot of time to learn all the crazy new terminal stuff! Yes, at this point, Ubuntu was already usable enough without the terminal, an accomplishment actually. But as a programmer, Ciro felt obliged to learn. Many hours were spent reading man pages at the library. But it all just felt so right, and sometimes powerful... true wizardry.

And ten years later, Ciro was seriously considering buying a computer without Windows pre-installed. He had not used Windows a single tie on a personal machine even once in those ten years!

Finally, to finish things off Ciro found two websites that changed his life forever, and made be believe that there was an alternative: Stack Overflow and GitHub.

The brutal openness of it all. The raw high quality content. Ugliness and uselessness too no doubt. But definitely spark in a sea of darkness.

Grew tremendously since the 1990's, likely linked to the Internet.

www.cbpp.org/wealth-concentration-has-been-rising-toward-early-20th-century-levels-2 shows historical for top 1% and 0.5% from 1920 to 2010.

TODO why is it so hard to find a proper cumulative distribution function-like curve? OMG. This appears to be also called a Lorenz curve.

Author of gwern.net.

Accounts:He posts insanely much on these websites. It's a bit like Ciro Santilli on Stack Overflow.

Ciro Santilli envies this guy a bit. He dumps his brain more or less full time on his highly customized static website partly due to early Bitcoin investments gwern.net/me says:

Also unsurprisingly he likes Haskell:

Ciro Santilli considers Gwern Ciro Santilli's e-soulmates due to his interest in "dark web things" like Bitcoin and Silk Road, his immense writing output in encyclopedic book-sized articles on a static website, and his desire to live frugally and just research and write all day. Ah, if only Ciro had some old coins!!!

This is likely a pseudonym, his real name not being publicly unknown, e.g. at news.ycombinator.com/item?id=5659278:

Equivalent to Lagrangian mechanics but formulated in a different way.

Motivation: Lagrangian vs Hamiltonian.

TODO understand original historical motivation, www.youtube.com/watch?v=SZXHoWwBcDc says it is from optics.

Intuitively, the Hamiltonian is the total energy of the system in terms of arbitrary parameters, a bit like Lagrangian mechanics.

Bibliography:

The most important program ever written!!!

A signal that indicates that an animal is ready for mating.

As if Greek letters weren't enough, physicists and mathematicians also like to make up tons of symbols, some of which look like the could actually be Greek letters!

Nabla is one of those: it was completely made up in modern times, and just happens to look like an inverted upper case delta to make things even more confusing!

Nabla means "harp" in Greek, which looks like the symbol.

Symmetric bilinear form that is also positive definite, i.e.:

TODO freely licensed image of sycees presented on a plate. This is how gifts/prizes would be formally handed in ancient China, possibly wrapped in silk to make it more discrete.