"Ciro" is "Cyrus" from Cyrus the Great in both Portuguese and Italian (although with very different pronunciations), thus doubly appropriate given that Ciro Santilli was born in Brazil, and has Italian ancestry.
After he conquered Babylon in 539 BC from the hands Neo-Babylonian Empire, Cyrus the Great did a great service to the Hebrews by allowing war prisoners that were held in Babylon to back to their home Judea, thus terminating the Babylonian captivity. These Jews were imprisoned because they had previously fought a war or revolted against the Neo-Babylonian Empire and lost. As Wikipedia puts it:
According to Isaiah 45:1 of the Hebrew Bible, God anointed Cyrus for this task, even referring to him as a messiah (lit. 'anointed one'); Cyrus is the only non-Jewish figure in the Bible to be revered in this capacity.
He is therefore viewed extremely positively in the good old book. Ciro was quite happy about this name choice by his father, given the human rights connotations of the figure and Ciro Santilli's self perceived compassionate personality.
Particularly fun things related to modern Cyrus are:
Because it belongs to some relatively obscure character of the Bible, the name it has been mostly passed on by writing to every single Christian country, and every single language came up with different way of saying it, because the only place they would possibly hear that name said out loud would be in Church!
As of 2020, the country in which the name is most popular in undoubtedly Italy. In Brazil, it is definitely not common, but also not completely unheard of either, e.g. Ciro Gomes is a notable Brazilian politician.
And Ciro responds to all the versions of the name that he knows of. These include:
  • English:
    • direct English reading of "Ciro" as "See Roll". Not the most cultured, but its what things tend to converge to, especially in highly international environments where it would be impossible to try and learn the origin of everyone's name! So it's fine. Slightly too close to "zero" for comfort.
    • Cyrus, the actual English version of the name. Ciro was so happy when his elderly English neighbour who went to Eton College, upon recognizing what Ciro was, immediately said: "Ah, Cyrus the Great!" He was the cutest, and he had some culture. Many/most English speaking people can't or won't be very sure about the spelling, but the sound of the name has a distinctly exotic feel to it, and the sounds are immediately recognized without sound ambiguity (unlike Ciro vs Zero).
  • French:
    • direct French reading of "Ciro" as "See Rho" with accent on Rho. This sounds exactly like "Sirop", i.e. Syrup in French, which can be good or bad depending on how you look at it.
    • Cyrus, the actual version of the name in French. Similar remarks to those of English apply.
  • Portuguese: "See Ru" with accent on See, and rolling r, and very weak "u". Some people might have some doubt of how to spell it and will ask for confirmation if needed, though many/most will get it right. Not particularly exotic like it is for English speakers.
  • Italian: "Chee Ro" with accent on Chee and rolling r. Widely understood and correctly spelled, more than in any other language. Not exotic at all, could be any random dude from Naples.
  • German: Kyrus. Because Cyrus the Great is known Kyrus II. (Cyrus the Second, his grandfather was also called Cyrus), Ciro once joked to a German friend that he should call him Kyrus III! He liked that.
and glad to add any new ones as they come.
  • Persian (spoken in 2020s Iran): something like Kurush. Likely the closest sound one to the original, though not sure how certain we can be of this.
He is actually quite happy when people use the name in their own language, because that means they understand the origin of the name.
Some Ciro's of interest:
Found through Google with no direct relation known to Ciro Santilli:
Possibly related variants:
Braindumping by Ciro Santilli 40 Updated 2025-07-16
There are two ways:
Ciro once told a friend that his ideal life would be to "just chill out and eat his bread in peace" (while also learning and teaching the sciences). Quote "Omar Khayyam's chill out quote" comes to mind. See also: Ciro Santilli's cheapness.
Ciro Santilli's knee by Ciro Santilli 40 Updated 2025-07-16
If Achilles' had his heel, Ciro had his knee.
First during University in Brazil while trying a kick up during the development of Cirodance his knee went a bit weird for a few weeks.
Then, just after arriving in France for École Polytechnique, the boys were playing indoor soccer, and to impress the girls Ciro was playing really hard, even took off his shirt, and suddenly when he was running by himself his knee snapped, he fell and it hurt like hell.
Ciro was on crutches for a few weeks, but the inflammation went away, but then he tried to play more soccer, but the knee was not as stable as before, and once he tried to run full speed, it slipped and hurt him a bit more (less severely) and so he gave up. For some reason it was not visible on the tomography made at the hospital.
Maybe Ciro should have investigated more though, certainly an experienced doctor could have done a hand pressure exam to determine which joint was damaged manually even. That was a medical failure.
So from this day on Ciro gave up on all interesting sports, and confined himself to more repetitive stuff like gym weights and cycling: Section "Ciro Santilli's sport practice". At Polytechnique he was forced to take up swimming as his mandatory sport, that was unbearably boring.
This defect is likely genetic since a close relative had similar problems.
But oh well, his then not-even girlfriend was impressed enough by the soccer or sorry enough for the sucker to marry him, so it worked out.
Ciro Santilli has an undiagnozed condition where his upper legs and lower torso often start to itch when he runs, to the point of being extremely annoying and removing all pleasure form the activity.
If some doctor knows why this could be, please tell him!!!
The problem is a bit hard to reproduce however, and Ciro hasn't been able to determine which exact condition triggers it: temperature, nutrition, something else?
Ciro believes that this is not chiefly due to transpiration, but rather to the impact motion that running does on the muscles, as he has felt something similar on his arms some times while cycling in very rough terrain, which made his arms shake in a similar fashion. or for example if he has a water bottle on a tightly tied backpack that rubs his back, then the back itches at that point.
Also, running on a threadmill is not a problem at all. Ciro believes that this is because the threadmill is better amortized, and therefore does not cause the same mechanical stress required to create the itching as running on pavement.
Interestingly, Ciro didn't feel that at all when he played soccer enthusiastically as a child, and he was one of the fastest runners of the group for sure at that time. So he's not sure if it started when he got older, or if it is just because the difference in workloads between soccer and running.
youtu.be/PNgYW5N95z8?t=945 "My back itches" after riding on a bumpy makeshift motorcycle.
This is how Ciro Santilli evaluates himself on the Big Five personality traits:
This is the kind of mind-bending argument twists that Ciro Santilli loves. If we take out the "a real child is hurt" aspect, does it still make sense to make it illegal?
Of course, hentai of young-looking girls has already existed since forever. Bit with newer image generation methods in the 2020s used for computer generated child pornography, especially sometimes photorealistic text-to-image generation, things are taken to another level.
Atom by Ciro Santilli 40 Updated 2025-07-16
Theory that atoms exist, i.e. matter is not continuous.
Much before atoms were thought to be "experimentally real", chemists from the 19th century already used "conceptual atoms" as units for the proportions observed in macroscopic chemical reactions, e.g. . The thing is, there was still the possibility that those proportions were made up of something continuous that for some reason could only combine in the given proportions, so the atoms could only be strictly consider calculatory devices pending further evidence.
Subtle is the Lord by Abraham Pais (1982) chapter 5 "The reality of molecules" has some good mentions. Notably, physicists generally came to believe in atoms earlier than chemists, because the phenomena they were most interested in, e.g. pressure in the ideal gas law, and then Maxwell-Boltzmann statistics just scream atoms more loudly than chemical reactions, as they saw that these phenomena could be explained to some degree by traditional mechanics of little balls.
Confusion around the probabilistic nature of the second law of thermodynamics was also used as a physical counterargument by some. Pais mentions that Wilhelm Ostwald notably argued that the time reversibility of classical mechanics + the second law being a fundamental law of physics (and not just probabilistic, which is the correct hypothesis as we now understand) must imply that atoms are not classic billiard balls, otherwise the second law could be broken.
Pais also mentions that a big "chemical" breakthrough was isomers suggest that atoms exist.
Very direct evidence evidence:
Less direct evidence:
Subtle is the Lord by Abraham Pais (1982) page 40 mentions several methods that Einstein used to "prove" that atoms were real. Perhaps the greatest argument of all is that several unrelated methods give the same estimates of atom size/mass:

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
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    Figure 1.
    Screenshot of the "Derivative" topic page
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    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
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    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
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