Intermediate filaments by Ciro Santilli 37 Updated +Created
Why is COVID-19 more serious than the flu? by Ciro Santilli 37 Updated +Created
These can be viewed at bitcoinstrings.com/blk00052.txt and are mostly commented on the "Wikileaks cablegate data" section of Hidden surprises in the Bitcoin blockchain by Ken Shirriff (2014).
Soon after block 229991 uploaded the Satoshi uploader, several interesting files were added to the blockchain using the uploader, and notably some containing content that might be illegal in certain countries, as a test to see if this type of content would make the Bitcoin blockchain illegal or not:
So basically, this was the first obviously illegal block attempt.
None of this content is particularly eye-popping for Ciro Santilli's slightly crazy freedom of speech standards, and as of 2021, the Bitcoin blockchain likely hasn't become illegal anywhere yet due to freedom of speech concerns.
Furthermore, it is likely much easier to find much worse illegal content by browsing any uncensored Onion service search engine for 2 minutes.
Ciro Santilli estimates that perhaps the uploader didn't upload child pornography, which is basically the apex of illegality of this era, because they were afraid that their identities would one day be found.
Bibliography:
Cool data embedded in the Bitcoin blockchain / Bibliography by Ciro Santilli 37 Updated +Created
Other Bitcon analysis:
GlobalFoundries by Ciro Santilli 37 Updated +Created
AMD just gave up this risky part of the business amidst the fabless boom. Sound like a wise move. They then fell more and more away from the state of the art, and moved into more niche areas.
TSMC by Ciro Santilli 37 Updated +Created
One of the companies that has fabs, which buys machines from companies such as ASML and puts them together in so called "silicon fabs" to make the chips
As the quintessential fabless fab, there is on thing TSMC can never ever do: sell their own design! It must forever remain a fab-only company, that will never compete with its customers. This is highlighted e.g. at youtu.be/TRZqE6H-dww?t=936 from Video "How Nvidia Won Graphics Cards by Asianometry (2021)".
Video 1.
How Taiwan Created TSMC by Asianometry (2020)
Source. Some points:
  • UCM failed because it focused too much on the internal market, and was shielded from external competition, so it didn't become world leading
  • one of TSMC's great advances was the fabless business model approach.
  • they managed to do large technology transfers from the West to kickstart things off
  • one of their main victories was investing early in CMOS, before it became huge, and winning that market
Alibaba Cloud by Ciro Santilli 37 Updated +Created
Atomic clock by Ciro Santilli 37 Updated +Created
Video 1.
How an atomic clock works, and its use in the global positioning system (GPS) by EngineerGuy (2012)
Source. Shows how conceptually an atomic clock is based on a feedback loop of two hyperfine structure states of caesium atoms (non-radioactive caesium-133 as clarified by the Wikipedia page). Like a quartz clock, it also relies on the piezoelectricity of quartz, but unlike the quartz clock, the quartz is not shaped like a tuning fork, and has a much larger resonating frequency of about 7 MHz. The feedback is completed by producing photons that resonate at the right frequency to excite the caesium.
Video 2.
Inside the HP 5061A Cesium Clock by CuriousMarc (2020)
Source.
A similar model was used in the Hafele-Keating experiment to test special relativity on two planes flying in opposite directions. Miniaturization was key.
Contains a disposable tube with 6g of Caesium. You boil it, so when it runs out, you change the tube, 40k USD. Their tube is made by Agilent Technologies, so a replacement since that opened in 1999, and the original machine is from the 60s.
Detection is done with an electron multiplier.
youtu.be/eOti3kKWX-c?t=1166 They compare it with their 100 dollar GPS disciplined oscillator, since GPS satellites have atomic clocks in them.
Video 3.
Quick presentation of the atomic clock at the National Physical Laboratory (2010)
Source. Their super accurate setup first does laser cooling on the caesium atoms.
Sandy Lerner by Ciro Santilli 37 Updated +Created
This chick is hardcore.
CERN experiment by Ciro Santilli 37 Updated +Created
FreeBSD by Ciro Santilli 37 Updated +Created
Black-body radiation experiment by Ciro Santilli 37 Updated +Created
Video 1.
Black-body Radiation Experiment by sciencesolution (2008)
Source. A modern version of the experiment with a PASCO scientific EX-9920 setup.
Antimatter by Ciro Santilli 37 Updated +Created
Klein-Gordon equation by Ciro Santilli 37 Updated +Created
A relativistic version of the Schrödinger equation.
Correctly describes spin 0 particles.
The most memorable version of the equation can be written as shown at Section "Klein-Gordon equation in Einstein notation" with Einstein notation and Planck units:
Has some issues which are solved by the Dirac equation:
Cryogen-free dilution refrigerator by Ciro Santilli 37 Updated +Created
Developmental genetics by Ciro Santilli 37 Updated +Created
How genes form bodies.
Video 1.
Developmental Genetics 1 by Joseph Ross (2020)
Source. Talks about homeobox genes.
When viewed as matrices, it is the group of all matrices that preserve the dot product, i.e.:
This implies that it also preserves important geometric notions such as norm (intuitively: distance between two points) and angles.
This is perhaps the best "default definition".
Product definition of the exponential function by Ciro Santilli 37 Updated +Created
The basic intuition for this is to start from the origin and make small changes to the function based on its known derivative at the origin.
More precisely, we know that for any base b, exponentiation satisfies:
  • .
  • .
And we also know that for in particular that we satisfy the exponential function differential equation and so:
One interesting fact is that the only thing we use from the exponential function differential equation is the value around , which is quite little information! This idea is basically what is behind the importance of the ralationship between Lie group-Lie algebra correspondence via the exponential map. In the more general settings of groups and manifolds, restricting ourselves to be near the origin is a huge advantage.
Now suppose that we want to calculate . The idea is to start from and then then to use the first order of the Taylor series to extend the known value of to .
E.g., if we split into 2 parts, we know that:
or in three parts:
so we can just use arbitrarily many parts that are arbitrarily close to :
and more generally for any we have:
Let's see what happens with the Taylor series. We have near in little-o notation:
Therefore, for , which is near for any fixed :
and therefore:
which is basically the formula tha we wanted. We just have to convince ourselves that at , the disappears, i.e.:
To do that, let's multiply by itself once:
and multiplying a third time:
TODO conclude.

There are unlisted articles, also show them or only show them.