Incoming links: Earth
Given experiments such as the Fizeau experiment and the Michelson-Morley experiment that couldn't really detect the Earth's movement across aether, people started to wonder if the Earth wasn't dragging the luminiferous aether.
Most of the helium in the Earth's atmosphere comes from alpha decay, since helium is lighter than air and naturally escapes out out of the atmosphere.
Wiki mentions that alpha decay is well modelled as a quantum tunnelling event, see also Geiger-Nuttall law.
As a result of that law, alpha particles have relatively little energy variation around 5 MeV or a speed of about 5% of the speed of light for any element, because the energy is inversely exponentially proportional to half-life. This is because:
- if the energy is much larger, decay is very fast and we don't have time to study the isotope
- if the energy is much smaller, decay is very rare and we don't have enough events to observe at all
- youtu.be/_f8zeEI0oys?t=796 George Gamow and Edward Condon proposed the quantum tunnelling explanation
- youtu.be/_f8zeEI0oys?t=1725 worked out example that predicts the half-life of polonium-210 based on its emission energy
First proper nearest galaxy to the Milky Way. Everything in the middle in the Local group is either a satellite of the Milky Way or Andromeda.
Many Andromeda satellite galaxies are simply numbered Andromeda II, Andromeda III and so on.
As described on Wikipedia, the observational history of Andromeda is fascinating. Little by little, people noticed that it had a different nature to many other objects observed on the sky, and the hypothesis that there are other galaxies like ours grew in force.
Part of our fascination with Andromeda is due to how similar in size and shape and close it is to the Milky Way.
It is clearly the only thing so large and so close.
Andromeda is, without a doubt, our sister galaxy.
One can't help but wonder if there is some alien looking back at us when we are looking at them through our Telescope.
Andromeda is also the furthest object from Earth that can be seen with the naked eye.[ref] Not surprising, as it literally shines with the strength of a trillion suns!
Highest resolution image of Andromeda as of 2015, taken by Hubble
. Source. Source also says it was the highest resolution image every released by the Hubble. This goes to show how fascinated people are by Andromeda. And there is good reason for it.Andromeda Shun from Saint Seiya performing his Nebula Chain attack
. Source. The original Japanese music actually says "Nebula Chain" in English. The Andromeda Galaxy is shown on the back, the chain appears to go all the way to it and back towards the evil guys' head. Not very relativistic, but so be it.Andromeda Galaxy with only a Camera, Lens, & Tripod by Nebula Photos (2020)
Source. Good job! Gives a good idea of the low end approach.Quick facts:
- Nationalities: Italian and Brazilian
- Grew up in: Brazil
- Relationship status 2017-: married
- Given name pronunciation: take your pick from Ciro Santilli's given name
- Chinese name: 三西猴, means "three western monkeys". Phonetic approximation to SANtilli CIRO. More info at: Ciro Santilli's Chinese name. Semi-unintentionally reminds Chinese people of Sun Wukong (孙悟空). This association is further slightly strengthened by the phonetic choice of 三 San, which Ciro later noticed matches the middle character of Tang Sanzang (唐三藏), the monk in Journey to the West. The given name 西猴 was given by Ciro Santilli's wife, then recent girlfriend, as a semi-joke, and he took it up because the best way to take a joke is to play along with the joker. 三 was chosen by Ciro himself.
- laptop: high end Lenovo ThinkPad
- distro: latest Ubuntu release
- Vim or Emacs: vi/vim. But for The Love, will someone please make an open source C++ integrated development environment that actually just works?
- tabs or spaces: spaces
- Mailing list or Git(Hub|Lab>): Git(Hub|Lab), with passion, see Section "Mailing list"
- system or unit tests: system
- programming languages: Python and C++. He'll learn Rust and Haskell once he's rich. As of the 2020s, Rust was picking up some serious steam, so Ciro might end up eating his own words there.
- musical instruments to listen: Chinese Guqin and electric Jazz-fusion guitar
- metric or imperial: metric, for The Love. Science? Standardization? 21st century anyone?
- QWERTY or Dvorak: QWERTY, alas
- birth name: Ciro Duran Santilli
Other people with the same name are listed at Section "Ciro Santilli's homonyms".
19th century illustration of the Journey to the West protagonist Sun Wukong
. Source. 
Sun Wukong (孙悟空) is a playful and obscenely powerful monkey Journey to the West. He protects Buddhist monk Tang Sanzang, and likes eating fruit, just like Ciro. Oh, and Goku from Dragon Ball is based on him. His japanese name is "Sun Wukong" (same Chinese characters with different Japanese pronunciation) for the love. His given name "Wukong" means literally "the one who mastered the void", which is clearly a Dharma name and fucking awesome in multiple ways. This is another sad instance of a Chinese thing better known in the West as Japanese.
It is worth noting however that although Wukong is extremely charming, Ciro's favorite novel of the Four Great Classic Novels is Water Margin. Journey to the West is just a Monster of the Week for kids, but Water Margin is a fight for justice saga. Sorry Wukong!
The photo was taken in an open event organized by the awesome Cambridge Synthetic Biology outreach group, more or less the same people who organize: www.meetup.com/Cambridge-Synthetic-Biology-Meetup/ and who helped organize Section "How to use an Oxford Nanopore MinION to extract DNA from river water and determine which bacteria live in it".
Taking part in such activities is what Ciro tries to do to overcome his lifelong regret of not having done more experimental stuff at university. Would he have had the patience to handle all the bullshit of the physical word without going back to the informational sciences? Maybe, maybe not. But now he will probably never know?!
Notice the orange high visibility cycling jersey under the lab coat, from someone who had just ridden in from work as fast as possible as part of his "lunch break". It is more fun when it is hard.
Scribe Jean Miélot, 15th century
. Ciro Santilli fantasizes that he would have make a good scribe in the middle ages, partly due to his self diagnosed graphomania, but also appreciation for foreign languages, and his mild obsession with the natural sciences.
OurBigBook.com is Ciro's view of a modern day scriptorium, except that now the illuminations are YouTube videos.
Chill and eat your bread in peace comes to mind. A scribe, in a library, reading and writing the entire day in peace and quiet. The life!
The job of a Internet-age scribe is basically that of making knowledge more open, legally extracting it from closed copyrighted sources, and explaining your understanding of it to the wider world under Creative Commons licenses on the web. And in the process of greater openness, given a well organized system, we are able combine the knowledge of many different people, and thus make things more understandable than any single/few creator closed source source could ever achieve.
Ciro once saw some cartoon on Wikipedia help pages of a turtle with a book in one hand, and typing into Wikipedia on its computer, TODO find it. That cartoon summarizes well the modern scribe life.
Another analogous version of this fantasy more in touch with Ciro's sinophily is the ideal of the Chinese scholar, notably including their stereotypical attributes such as mastery of the Four arts.
Ciro Santilli piling boxes as a child
. A natural born engineer.
Ciro Santilli waving hello in infrared.
More info at: Figure "Ciro Santilli waving hello in infrared".A law of physics is Galilean invariant if the same formula works both when you are standing still on land, or when you are on a boat moving at constant velocity.
For example, if we were describing the movement of a point particle, the exact same formulas that predict the evolution of must also predict , even though of course both of those will have different values.
It would be extremely unsatisfactory if the formulas of the laws of physics did not obey Galilean invariance. Especially if you remember that Earth is travelling extremelly fast relative to the Sun. If there was no such invariance, that would mean for example that the laws of physics would be different in other planets that are moving at different speeds. That would be a strong sign that our laws of physics are not complete.
The consequence/cause of that is that you cannot know if you are moving at a constant speed or not.
Lorentz invariance generalizes Galilean invariance to also account for special relativity, in which a more complicated invariant that also takes into account different times observed in different inertial frames of reference is also taken into account. But the fundamental desire for the Lorentz invariance of the laws of physics remains the same.
Looking at most astronomical object through a Telescope is boring because you only see a white ball or point every time. Such targets would likely only be interesting with spectroscopy analysis.
There are however some objects that you can see the structure of even with an amateur telescope, and that makes them very exciting.
Some good ones:
- The Moon, notably crater detail.
- Saturn. Clearly visible to the naked eye, but looks like a ball. But under an amateur telescope, you can clearly see that there is a disk. Clearly discerning that the disk is a ring, i.e. seeing the gap, is a bit harder though.
- Jupiter. Clearly visible to the naked eye, it is quite huge. The four Galilean moons, being Earth-sized, are incredibly clearly visible, tested on Celestron NexStar 4SE 25mm/9mm eyepiece. Colored gas clouds are hard though, you will likely just see it bright white. www.reddit.com/r/telescopes/comments/35xrbb/how_can_i_see_the_color_of_jupiter_with_my/
- a double star. As mentioned at www.relativelyinteresting.com/10-astronomical-targets-new-telescope/ Albireo are incredibly separated. Also it is is easy to find manually being in a major well known constellation. It is no wonder it is not quite even known if they are gravitationally bound or not!
- Andromeda Galaxy. This is when things start getting hard. You can see a faint cloud, but it is not super clear that it has a center.One important understanding is that it is not possible to see stars outside of the Milky Way by naked eye.It is at this point that you start to learn that pictures of faint objects require longer term exposure and averaging of the images taken. For this you need:Just looking through the scope to immediately see something is not enough.
- a digital camera attached to the scope
- a computerized scope that slowly moves to track the point of interest
- image processing software that does the averaging
Video "Andromeda Galaxy with only a Camera, Lens, & Tripod by Nebula Photos (2020)" gives a good notion of expectation adjustment.
It is hard for complex organisms to evolve because longer DNA means longer replication time Updated 2025-02-22 +Created 1970-01-01
Because DNA replication is a key limiting factor of bacterial replication time, such organisms are therefore strongly incentivized to have very minimal DNAs.
Power, Sex, Suicide by Nick Lane (2006) 7 "Why bacteria are simple" page 169 puts this nicely:
Bacteria replicate at colossal speed. [...] In two days, the mass of exponentially doubling E. coli would be 2664 times larger than the mass of the Earth.Luckily this does not happen, and the reason is that bacteria are normally half starved. They swiftly consume all available food, whereupon their growth is limited once again by the lack of nutrients. Most bacteria spend most of their lives in stasis, waiting for a meal. Nonetheless, the speed at which bacteria do mobilize themselves to replicate upon feeding illustrates the overwhelming strength of the selection pressures at work.
Hardcoded and unique network addresses for every single device on Earth.
Started with 48 bits (6 bytes), usually given as 01:23:45:67:89:AB but people now encouraged to use 64-bit ones.
How they are assigned: www.quora.com/How-are-MAC-addresses-assigned Basically IEEE gives out the 3 first bytes to device manufacturers that register, this is called the organizationally unique identifier, and then each manufacturer keeps their own devices unique.
Because they interact weakly with matter and mostly just escape out of nuclear reactors, you can likely locate all nuclear reactors on Earth by measuring neutrino flows:The CIA must love that shit, they must have had it years prior to this public paper.
The only isotope found on Earth because it occurs as part of the uranium 238 decay chain, i.e., it is not a primordial nuclide.
Interestingly it is a bit less stable than other isotopesL such as Polonium-208 (3 y) and Polonium-209 (124 y), but those aren't in any Earthly radioactive chain so they don't show up on Earth.
Video 1. Alegria, Alegria by Caetano Veloso (1968)Source. Critique of Military dictatorship in Brazil.
- 1972
- Transa (1972) album. Literally: "The Fuck", good old seventies. Caetano himself later mentions that this is one of his own favorite albums.[ref] The album was composed when he was living in London.
Video 2. Triste Bahia by Caetano Veloso (1972)Source. Inspired by (or more likely: actually is) capoeira music.Video 3. Mora na Filosofia by Caetano Veloso (1972)Source.
Video 4. Você Não Entende Nada by Caetano Veloso (1970)Source.Amazing performance at Coliseu dos Recreios, Lisbon. 1981. Discogs says original album is Legal (1970), but wiki page and photos of back disagree...This song talks about a man's mixed desires to remain with his partner and also escape to adventure. It contains one of the most amazing sexual innuendo ever recorded: the man describes foods that his partner will serve him, and the he endlessly eats and eats and eats:translation:eu como, eu como, eu como, você [... huge intentional pause ...] não está entendendo quase nada do que eu digo.
which makes it unclear "you" is part of "I eat you" (to eat (comer) is a slang for fucking), or if "you" is part of the next sentence.I eat, I eat, I eat, you [... huge intentional pause ...] don't understand anything that I'm saying.
Video 5. Partido Alto by Caetano Veloso (1972)Source. Atheism song (theodicy)! Lyrics by Chico Buarque, but Ciro Santilli prefers this interpretation. From the 1972 "Caetano E Chico Juntos E Ao Vivo" joint album with Chico Buarque.
- 1975 Qualquer coisa album
Video 6. Qualquer Coisa by Caetano Veloso (1975)Source.Video 7. Samba e Amor by Caetano Veloso (1975)Source. Cover from original song by Chico Buarque, original album Chico Buarque de Hollanda - Nº4. Desperately reminds Ciro of his University day weekend nights. Except that there was no Samba. And little Amor. Mostly a silent and wholesome loneliness and emulation.Video 8. Georde de Capadócia by Caetano Veloso (1975)Source.Composed by Jorge Ben, but this interpretation is remarkable. corpo fechado (closed body) style song. This idea is much linked to Capoeira/African religion idea. E.g. a more traditional capoeira corpo fechado song: www.youtube.com/watch?v=tfd9j6XFmSgVideo 9. Coricos' prayer scene from Black God, White Devil (1964)Source. This shows an Amazing corpo fechado scene from an amazing old black an white Brazilian film.
- 1976 Doces Bárbaros (1976) album
Video 10. Um Índio by Caetano Veloso (1976)Source. Recording from 1992. Also appeared in the Bicho (1977) album. - 1977 Bicho (1977)
Video 11. Tigresa by Caetano Veloso (1977)Source. Talks about a strong willed, unapologetic, disenchanted, but also hopeful brown skinned lover: a tigress. Ciro once knew one, but it wasn't meant to be.
- 1978 album Muito (Dentro da Estrela Azulada)
Video 12. Sampa by Caetano Veloso (1978)Source."Sampa" is an affectionate slang for São Paulo City. The song perfectly captures the city, and reminds Ciro so badly of his University days there.[D]a força da grana que ergue e destroi coisas belas
The power of money that builds and destroy beautiful thingsVideo 13. Terra by Caetano Veloso (1978)Source."Terra" means Earth in Portuguese.Ciro used to watch a television nature show called "Planeta Terra" in the legendary TV Cultura with his parents in the couch when he was young, and under a duvet when it was a bit cold. Those days were the best. The narrator's lady voice was particularly soothing, and would easily put you in a kind of sleepy trance, her name is Valéria GrilloTODO what was the original show exactly? Here is a sample: www.youtube.com/watch?v=vNwfYEMdrRU Very likely just a translation of some British nature show with a custom Brazilian intro and presenter. Credits at end mention English narrator: "Eugene Fraser", and "Thirteen WNET Nature" production, which produced Nature (1982) that ran since 1982, making that a likely candidate. - 1980
Video 14. Menino do Rio by Caetano Veloso (1980)Source. Apparently served as inspiration for the Menino do Rio (1980) movie, which is silly, but a worthwhile record of the times. - 1984 Velô (1984)
Video 15. O Quereres by Caetano Veloso (1984)Source. Notable quote from the chorus that is often in Ciro's mind:translation:Ah, bruta flor, do querer
Oh, brute flower of the wanting