Micro Bit getting started Updated +Created
When plugged into Ubuntu 22.04 via the USB Micro-B the Micro Bit mounts as:
/media/$USER/MICROBIT/
e.g.:
/media/ciro/MICROBIT/
for username ciro.
Loading the program is done by simply copying a .hex binary into the image e.g. with:
cp ~/Downloads/microbit_program.hex /media/$USER/MICROBIT/
The file name does not matter, only the .hex extension.
The back power light flashes while upload is happening.
Flashing takes about 10-15 seconds for the 1.8 MB scroll display hello world from microbit-micropython.readthedocs.io/en/v1.0.1/tutorials/hello.html:
from microbit import *
display.scroll("Hello, World!")
and the program starts executing immediately after flash ends.
You can restart the program by clicking the reset button near the USB. When you push down the program dies, and it restarts as soon as you release the button.
nRF51 series Updated +Created
Micro Bit example Updated +Created
Not safe for work Updated +Created
Mahayana sutra Updated +Created
Path integral formulation Updated +Created
This one might actually be understandable! It is what Richard Feynman starts to explain at: Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979).
The difficulty is then proving that the total probability remains at 1, and maybe causality is hard too.
The path integral formulation can be seen as a generalization of the double-slit experiment to infinitely many slits.
Feynman first stared working it out for non-relativistic quantum mechanics, with the relativistic goal in mind, and only later on he attained the relativistic goal.
TODO why intuitively did he take that approach? Likely is makes it easier to add special relativity.
This approach more directly suggests the idea that quantum particles take all possible paths.
Compile MicroPython code for Micro Bit locally Updated +Created
To use a prebuilt firmware, you can just use uflash, tested on Ubuntu 22.04:
git clone https://github.com/bbcmicrobit/micropython
cd micropython
git checkout 7fc33d13b31a915cbe90dc5d515c6337b5fa1660
uflash examples/led_dance.py
What that does is:
  • convert the MicroPython code to bytecode
  • join it up with a prebuilt firmware that ships with uflash which contains the MicroPython interpreter
  • flashes that
To build your own firmware see:
Micro Bit version Updated +Created
Identification: kitronik.co.uk/blogs/resources/explore-micro-bit-v1-microbit-v2-differences The easiest thing is perhaps the GPIO notches.
Carrier wave Updated +Created
Early transmitters such as the spark-gap transmitter could only send noises to send Morse code.
To send voice and music, amplitude modulation had to be developed. And a key ingredient of this is the carrier wave.
The problem is, the carrier wave needs to have somewhat high frequencies, in the hundreds of kHz TODO why. But as you might imagine, that is hard to achieve by mechanical means such as a hand cranck like Hippolyte Pixiis alternator!
Interestingly, some of the first carrier wave generators were actually mechanical, e.g. the Alexanderson alternator.
But clearly such mechanical machines were not very scalable, and soon more electronic devices were introduced, notably the vacuum tube.
Fructose Updated +Created
Weak interaction Updated +Created
Explains beta decay. TODO why/how.
Maybe a good view of why this force was needed given beta decay experiments is: in beta decay, a neutron is getting split up into an electron and a proton. Therefore, those charges must be contained inside the neutron somehow to start with. But then what could possibly make a positive and a negative particle separate?
www.thestargarden.co.uk/Weak-nuclear-force.html gives a quick and dirty:
Beta decay could not be explained by the strong nuclear force, the force that's responsible for holding the atomic nucleus together, because this force doesn't affect electrons. It couldn't be explained by the electromagnetic force, because this does not affect neutrons, and the force of gravity is far too weak to be responsible. Since this new atomic force was not as strong as the strong nuclear force, it was dubbed the weak nuclear force.
Also interesting:
While the photon 'carries' charge, and therefore mediates the electromagnetic force, the Z and W bosons are said to carry a property known as 'weak isospin'. W bosons mediate the weak force when particles with charge are involved, and Z bosons mediate the weak force when neutral particles are involved.
Video 1. Source. Some decent visualizations of the field lines.
Pinto bean Updated +Created
This seems to be the "brown Brazilian bean" that many Brazilians eat every day.
Edit: after buying it, not 100% sure. This one felt smaller than what Ciro had in Brazil, borlotti beans might be closer. Pinto beans are smaller, and creamier, and have softer peel, possibly produced less natural gas.
2021-04: second try.
2021-03: did for first time, started with same procedure as borlotti beans 2021-03. Maybe 1h30 is too much. Outcome was still very good.
Ciro Santilli's wedding Updated +Created
Figure 1.
Ciro Santilli with his soon-to-be Ciro Santilli's mother-in-law during his wedding in 2017
.
webpack Updated +Created
Webpack is like a magic hydra that can eat any type of file and bundle it into a single output: .js, .ts, .ccs, .scss, .jsx, .tsx, require, import, import css from .js, it doesn't matter at all, it just digests all into the same dump.
When it works, you are just left in awe and with a single Js file. When it doesn't, you're fucked and have to debug for several hours.
Demos under: webpack/. To run all of them by default:
cd webpack/min
npm install
npm run build
xdg-open index.html
To easily make changes and reload the .js output live let this run on a terminal:
npx webpack watch
Examples:
Quantum field theory lecture notes Updated +Created
Lecture notes found by Googling "quantum field theory pdf":
Bill Gates Updated +Created
The enemy?
It does not matter how many trillions you donate to charity, Bill. If you want to prove your point, make MS Word free and open source and port it to Linux. And then Window implements POSIX-compatible APIs and then deprecate non-POSIX APIs.

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