Why do the electron and the proton have the same charge except for the opposite signs? Updated 2024-10-28 Created 1970-01-01
Given the view of the Standard Model where the electron and quarks are just completely separate matter fields, there is at first sight no clear theoretical requirement for that.
As mentioned e.g. at QED and the men who made it: Dyson, Feynman, Schwinger, and Tomonaga by Silvan Schweber (1994) chapter 1.6 "Hole theory", Dirac initially wanted to think of the holes in his hole theory as the protons, as a way to not have to postulate a new particle, the positron, and as a way to "explain" the proton in similar terms. Others however soon proposed arguments why the positron would need to have the same mass, and this idea had to be discarded.
This is basically how quantum computing was first theorized by Richard Feynman: quantum computers as experiments that are hard to predict outcomes.
TODO answer that: quantumcomputing.stackexchange.com/questions/5005/why-it-is-hard-to-simulate-a-quantum-device-by-a-classical-devices. A good answer would be with a more physical example of quantum entanglement, e.g. on a photonic quantum computer.
Why it takes several days to enter inflammatory phase in COVID-19? Updated 2024-10-28 Created 1970-01-01
Why is it there such a clear separation of phases?
Why do people with mild symptoms go on to die? It is a great mystery.
Ciro Santilli's theory is that COVID is extremely effective at avoiding immune response. Then, in people where this is effective, things reach a point where there is so much virus, that the body notices and moves on to take a more drastic approach. This is compatible with the virus killing older people more, as they have weaker immunes systems. This is however incompatible with the fact that people don't seem to be contagious after the viral phase is over...
- physics.stackexchange.com/questions/26797/why-does-work-equal-force-times-distance
- www.quora.com/Why-do-we-define-work-as-force-times-distance
- physics.stackexchange.com/questions/428525/why-does-work-depend-on-distance
- physics.stackexchange.com/questions/79523/why-does-the-amount-of-energy-transferred-depend-on-distance-rather-than-time
This is meant to be an answer to: diy.stackexchange.com/questions/27669/how-can-i-thoroughly-blackout-a-bedroom-window-on-a-budget but that question was protected and I can't answer right now because I don't have 10 reputation on the website, so here goes.
Using the TLB makes translation faster, because the initial translation takes one access _per TLB level_, which means 2 on a simple 32 bit scheme, but 3 or 4 on 64 bit architectures.
The TLB is usually implemented as an expensive type of RAM called content-addressable memory (CAM). CAM implements an associative map on hardware, that is, a structure that given a key (linear address), retrieves a value.
Mappings could also be implemented on RAM addresses, but CAM mappings may required much less entries than a RAM mapping.
For example, a map in which:could be stored in a TLB with 4 entries:
- both keys and values have 20 bits (the case of a simple paging schemes)
- at most 4 values need to be stored at each time
linear physical
------ --------
00000 00001
00001 00010
00010 00011
FFFFF 00000
However, to implement this with RAM, _it would be necessary to have 2^20 addresses_:
which would be even more expensive than using a TLB.
linear physical
------ --------
00000 00001
00001 00010
00010 00011
... (from 00011 to FFFFE)
FFFFF 00000
Was adopted by AskJeeves in 2001.
The Google Story Chapter 11. "The Google Economy" comments:
As they saw it, generation one was AltaVista, generation two was Google, and generation three was Teoma, or what Ask Jeeves came to refer to as Expert Rank. Teoma's technology involved mathematical formulas and calculations that went beyond Google's PageRank system, which was based on popularity. In fact, the concept had been cited in the original Stanford University paper written by Sergey Brin and Larry Page as one of the methods that could be used to rank indexed Web sites in response to search requests. "They called their method global popularity and they called this method local popularity, meaning you look more granularly at the Web and see who the authoritative sources are," Lanzone said. He said Brin an Page had concluded that local popularity would be exceedingly difficult to execute well, because either it would require too much processing power to do it in real time or it would take too long.
googlesystem.blogspot.com/2006/03/expertrank-authoritative-search.html mentions
and:
ExpertRank is an evolution of IBM's CLEVER project, a search engine that never made it to public.
The difference between PageRank and ExpertRank is that for ExpertRank the quality of the page is important and that quality is not absolute, but it's relative to a subject.
There are other more recent algorithms with similar names, and are prehaps related:
- www.researchgate.net/publication/257015904_ExpertRank_A_topic-aware_expert_finding_algorithm_for_online_knowledge_communities ExpertRank: A topic-aware expert finding algorithm for online knowledge communities (2013)
- ieeexplore.ieee.org/document/5260966 ExpertRank: An Expert User Ranking Algorithm in Online Communities
Cirocoins are the most valuable form of currency that exists at any point.
Cirocoins can only be issued by Ciro Santilli.
Cirocoins are strictly nominal, and cannot be traded by recipients with anyone but Ciro, i.e. they are extremely illiquid.
Cirocoins can be removed from recipients at any point if they commit non-Cirist acts.
It is not possible to give a precise number to how many Cirocoins anyone owns. This is decided on a transaction by transaction basis. Ciro can therefore only inform you if your Cirocoin balance increased or decreased, but any attached number has no value, and thus are equivalent to expressions of type "you gained/lost a Cirocoin".
The following inferior currencies come to mind:
Got it working as mentioned at: github.com/cirosantilli/feathers-chat/tree/sequelize-pg
Bibliography:
There's also a
heroku
branch at: github.com/feathersjs/feathers-chat/tree/heroku, but it also seems to use NeDB? So you can have a filesystem in Heroku? Doesn't seem so: stackoverflow.com/questions/42775418/heroku-local-persistent-storageThis is true. The level of competition in university entry exams in Asia in insane in the early 21st century compared to the West.
This is actually both good and bad. Good because it selects some very good exam passers. And bad because it selects some very good exam passers.
Wikipedia mentions quoting his Nobel Prize biography:
In Monod's studies he discovered that the course work was decades behind the current biological science. He learned from other students a little older than himself, rather than from the faculty.
Feynman was a huge womanizer during a certain period of his life Updated 2024-10-28 Created 1970-01-01
Feynman became a terrible womanizer after his first wife Arline Greenbaum died, involving himself with several married women, and leading to at least two abortions according to Genius: Richard Feynman and Modern Physics by James Gleick (1994).
Ciro Santilli likes to think that he is quite liberal and not a strict follower of Christian morals, but this one shocked him slightly even. Feynman could be a God, but he could also be a dick sometimes.
One particular case that stuck to Ciro Santilli's mind, partly because he is Brazilian, is when Feynman was in Brazil, he had a girlfriend called Clotilde that called him "Ricardinho", which means "Little Richard"; -inho is a diminutive suffix in Portuguese, and also indicates affection. At some point he even promised to take her back to the United States, but didn't in the end, and instead came back and married his second wife in marriage that soon failed.
Richard's third and final wife, Gweneth Howarth, seemed a good match for him though. When they started courting, she made it very clear that Feynman should decide if he wanted her or not soon, because she had other options available and being actively tested. Fight fire with fire.
Video with a solid color:
- 2 second white video:
Also add some audio:
ffplay -autoexit -f lavfi -i 'color=white:640x480:d=3,format=rgb24,trim=end=2'
TODO how to ffplay the video + audio directly?ffmpeg -lavfi "color=white:640x480:d=3,format=rgb24,trim=end=2[v];sine=f=1000:d=2[a]" -map '[a]' -map '[v]' out.mkv
-map
does not seem to work unfortunately. - 2 second white followed by 2 second black video:
ffplay -autoexit -f lavfi -i 'color=white:640x480:d=3,format=rgb24,trim=end=2[a];color=black:640x480:d=3,format=rgb24,trim=end=2[b];[a][b]concat=n=2:v=1:a=0'
- bibliography:
Display count in seconds on the video:
- black text on white background. Start from 0 and count up to 2:
ffplay -autoexit -f lavfi -i " color=white:480x480:d=3, format=rgb24, drawtext= fontcolor=black: fontsize=600: text='%{eif\:t\:d}': x=(w-text_w)/2: y=(h-text_h)/2 "
- bibliography:
TODO possible? superuser.com/questions/559768/ffplay-how-to-play-together-separate-video-and-audio-files
For synthesized streams like
but it does not seem to accept multiple
fails with:
sine
we can do it e.g.
ffplay -autoexit -nodisp -f lavfi -i '
sine=frequency=500[a];
sine=frequency=1000[b];
[a][b]amerge, atrim=end=2
'
-i
for some reason. So is there a way to open a file from some filter? E.g.:
ffplay -i tmp.wav -i tmp.mkv -filter_complex "[0:a]atrim=end=2[a];[1:v]trim=end=2[v]" -map '[a]' -map '[v]'
Argument 'tmp.mkv' provided as input filename, but 'tmp.wav' was already specified.
Maybe Ciro Santilli should do something useful and remarkable so that someone might actually want to read his biography in the first place. But hey, procrastination.
Ciro Santilli was born in Brazil in the small/medium city of Rio Claro, São Paulo (~200k people in 2020) in the State of São Paulo in 1989 AD.
The family then moved to Jundiaí in 1995, and then finally to Santos, São Paulo, Brazil in 1997.
At the age of 10, Ciro Santilli spent 10 months in Coventry, United Kingdom, where he greatly improved his English.
After Coventry, Ciro's family went back to Santos, São Paulo, Brazil, which made a deep impression on Ciro, until he Ciro Santilli's undergrad studies at the University of São Paulo in 2007.
In 2010, as mentioned atSection "Ciro Santilli's formal education", Ciro as admitted in a double degree program at the École Polytechnique, France, where he stayed until 2013. Going to France was a mind blowing, life changing event.
There are unlisted articles, also show them or only show them.