Ciro Santilli @cirosantilli 35

The 3D regular convex polyhedrons are super famous, have the name: Platonic solid, and have been known since antiquity. In particular, there are only 5 of them.

The counts per dimension are:

The cool thing is that the 3 that exist in 5+ dimensions are all of one of the three families:Then, the 2 3D missing ones have 4D analogues and the sixth one in 4D does not have a 3D analogue: the 24-cell. Yes, this is the kind of irregular stuff Ciro Santilli lives for.

ISO is the main culprit of this bullshit, some notable examples related to open source software:

The only low level thing that escaped this was OpenGL via Khronos, what heroes those people are.

How the hell are you supposed to develop an open source implementation of something that has a closed standard?

Not to mention open source test suites, that would be way too much to ask for, those always end up being made by some shady small companies that go bankrupt from time to time, see e.g. .

Basically the opposite of security through obscurity, though slightly more focused on cryptography.

For a commented initial example, see: e. Coli K-12 MG1655 gene thrA.

KEGG does the visual maps well.

But BioCyc is generally better otherwise.

Whole organism simulation of C. elegans.

High level simulation only, no way to get from DNA to worm! :-) Includes:

3D body viewer at: browser.openworm.org/ TODO can you click on a cell to get its name?

The by far dominating DNA sequencing company of the late 2000's and 2010's due to having the smallest cost per base pair.

Illumina actually bought their 2010's dominating technology from a Cambridge company called Solexa.

To understand how Illumina's technology works basically, watch this video: Video 1. "Illumina Sequencing by Synthesis by Illumina (2016)".

The key innovation of this method is the Bridge amplification step, which produces a large amount of identical DNA strands.

2023 full connectome published on Science by Marta Zlatic's lab at the MRC:

The hard part then is how to make any predictions from it:

2024: www.nature.com/articles/d41586-024-03190-y Largest brain map ever reveals fruit fly's neurons in exquisite detail

As of 2022, it had been almost fully decoded by post mortem connectome extraction with microtome!!! 135k neurons.

That article mentions the humongous paper elifesciences.org/articles/66039 elifesciences.org/articles/66039 "A connectome of the Drosophila central complex reveals network motifs suitable for flexible navigation and context-dependent action selection" by a group from Janelia Research Campus. THe paper is so large that it makes eLife hang.

First sequenced variant: www.ncbi.nlm.nih.gov/genome/?term=86693

Genes at: www.ncbi.nlm.nih.gov/nuccore/MN908947.3 TODO protein list on a database?

30kbp, 10 genes, 29 proteins: cen.acs.org/biological-chemistry/infectious-disease/know-novel-coronaviruss-29-proteins/98/web/2020/04

50-200 nanometers in diameter.

Gene overview:

Stack overflow allows deleting content/making it visible only to 10k rep users.

Ciro Santilli is strictly against this, and this is an intended core policy of OurBigBook.com.

If you delete people's content randomly, they will be much less likely to write anything.

Getting downvoted to oblivion is one thing, but data loss? Unacceptable.

Only illegal content must ever be deleted. Or extremely obvious spam. But anything in a gray area should never be removed.

Deletion can be done by either:

The most practical/precise volt standard.

It motivated the definition of the ampere in the 2019 redefinition of the SI base units

Good NIST articles about it: (archive)

The wiki page en.wikipedia.org/wiki/Josephson_voltage_standard contains amazing schematics of the device, apparently made by the US Government.

This makes it clear how the Lie bracket can be seen as a "measure of non-commutativity"

Because the Lie bracket has to be a bilinear map, all we need to do to specify it uniquely is to specify how it acts on every pair of some basis of the Lie algebra.

Then, together with the Baker-Campbell-Hausdorff formula and the Lie group-Lie algebra correspondence, this forms an exceptionally compact description of a Lie group.

This section is about the definition of the dot product over ${\mathbb{C}}^n$, which extends the definition of the dot product over ${\mathbb{R}}^n$.

Some motivation is discussed at: math.stackexchange.com/questions/2459814/what-is-the-dot-product-of-complex-vectors/4300169#4300169

The complex dot product is defined as:

E.g. in ${\mathbb{C}}^1$:

We can see therefore that this is a form, and a positive definite because:

Just like the usual dot product, this will be a positive definite symmetric bilinear form by definition.

In the context of Maxwell's equations, it is vector field that is one of the inputs of the equation.

Section "Maxwell's equations with pointlike particles" asks if the theory would work for pointlike particles in order to predict the evolution of this field as part of the equations themselves rather than as an external element.

Measured in amperes in the International System of Units.

Heinrich Hertz's main initial experiment used a spark-gap transmitter. It is not something that transmits recorded sounds like voice: it only transmits noisy beeps. And as such was used for wireless telegraphy.

This is what happens when you apply a DC voltage across a Josephson junction.

It is called "AC effect" because when we apply a DC voltage, it produces an alternating current on the device.

By looking at the Josephson equations, we see that $V(t)=k$ a positive constant, then $\phi$ just increases linearly without bound.

Therefore, from the first equation:we see that the current will just vary sinusoidally between $\pm I_c$.

This meas that we can use a Josephson junction as a perfect voltage to frequency converter.

Wikipedia mentions that this frequency is $484GHz/mV$, so it is very very high, so we are not able to view individual points of the sine curve separately with our instruments.

Also it is likely not going to be very useful for many practical applications in this mode.

An I-V curve can also be seen at: Figure "Electron microscope image of a Josephson junction its I-V curve".

Their only undergraduate courses that matter:

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:

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:

Bibliography: