Ciro Santilli @cirosantilli 37

As usual, it is useful to think about how a bilinear form looks like in terms of vectors and matrices.

Unlike a linear form, which was a vector, because it has two inputs, the bilinear form is represented by a matrix $M$ which encodes the value for each possible pair of basis vectors.

In terms of that matrix, the form $B(x,y)$ is then given by:

The matrix ring of degree n $M_n$ is the set of all n-by-n square matrices together with the usual vector space and matrix multiplication operations.

This set forms a ring.

Related terminology:

This construction takes as input:and it produces an elliptic curve over a finite field of order $p$ as output.

The constructions is used in the Birch and Swinnerton-Dyer conjecture.

To do it, we just convert the coefficients $a$ and $b$ from the Equation "Definition of the elliptic curves" from rational numbers to elements of the finite field.

For example, suppose we have $a=3/4$ and we are using $p=11$.

For the denominator $4$, we just use the multiplicative inverse, e.g. supposing we havewhere $4^{-1}=3\mathrm{mod}11$ because $4\times 3=1\mathrm{mod}11$, related: math.stackexchange.com/questions/1204034/elliptic-curve-reduction-modulo-p

Bought: January 2020 from store.google.com/ for 350 pounds.

Official specs: support.google.com/pixelphone/answer/7158570?hl=en&ref_topic=7530176

GMS Arena: www.gsmarena.com/google_pixel_3a-9408.php

Front camera video on Android 11: about 100MiB / minute. The encoding is however super inefficient, a FFmpeg re-encode without any options reduces it by 1/3.

For Fastboot mode: Power and Volume down simultaneously for 10-15s. It is OK if screen sleeps. On "no command", power then volume up to see options.

2023-10: touchscreen not registering touches anymore. Still displays images. Manage to regain access with wired USB mouse + a simple USB-C adapter. RIP. Will attempt replacement: store.ifixit.co.uk/products/google-pixel-3a-screen-genuine?variant=42388954448071, partly to get Authy access which I had never properly tested... Replaced screen, but at exact same status as before: shows image but no touch. thus I wasted my money and time (minus the learning) something else is broken.

This has annoyed Ciro Santilli for many years, it is just too wasteful of screen space on laptops!

Or likely more generally, on GNOME desktop, which is the default desktop environment as of Ubuntu 22.10.

Issues:

Ciro once read that there are two types of mathematicians/scientists (he thinks it was comparing Einstein to some Jack of all trades polymath who didn't do any new discoveries):

TODO long after Ciro forgot where he had read this from originally, someone later pointed him to: www.ams.org/notices/200902/rtx090200212p.pdf Birds and Frogs by Freeman Dyson (2009), which is analogous but about Birds and Frogs. So did Ciro's memory play a trick on him, or is there also a variant; of this metaphor with a gopher?

Ciro is without a doubt the bird type. Perhaps the ultimate scientist is the one who can combine both aspects in the right amount?

Ciro gets bored of things very quickly.

Once he understands the general principles, if the thing is not the next big thing, Ciro considers himself satisfied without all the nitty gritty detail, and moves on to the next attempt.

In the field of mathematics for example, Ciro is generally content with understanding cool theorem statements. More generally, one of Ciro's desires is for example to understand the significance of each physics Nobel Prize.

This is also very clear for example after Ciro achieved Linux Kernel Module Cheat: he now had the perfect setup to learn all the Linux kernel shady details but at the same time after all those years he finally felt that "he could do it, so that was enough", and soon moved to other projects.

If Ciro had become a scientist, he would write the best review papers ever, just like in the current reality he writes amazing programming tutorials on Stack Overflow.

Ciro has in his mind an overly large list of subjects that "he feels he should know the basics of", and whenever he finds something in one of those topics that he does not know enough about, he uncontrollably learns it, even if it is not the most urgent thing to be done. Or at least he puts a mention on his "list of sources" about the subject. Maybe everyone is like that. But Ciro feels that he feels this urge particularly strongly. Correspondingly, if a subject is not in that list, Ciro ignores it without thinking twice.

Ciro believes that high flying birds are the type of people better suited for venture capital investment management: you know a bit of what is hot on several fields to enough depth to decide where to place your bets and how to guide them. But you don't have the patience to actually go deeply into any one of them and deal with each individual shit that comes up.

Cosmos: A Personal Voyage (1980) episode 1 mentions as quoted by the Wikipedia page for Eratosthenes:That's Ciro.

Some related ideas:

This is the exact model: shop.elica.com/en/accessori/filtro-grassi-in-alluminio-cod-gf03fc.html | web.archive.org/web/20190707053526/https://shop.elica.com/en/accessori/filtro-grassi-in-alluminio-cod-gf03fc.html

Searching by th epart name "GF03FC" leads to other sellers besides Elica however, which could reduce shipping costs: www.cookerhoodsupplies.co.uk/filters-and-lamps/188-metal-grease-filter-gf03fc.html

Brand on extractor glass: Elica: elica.com

Dimensions: 45.9cm x 17.6cm on the exterior. Too long to fit into any container that we have.

Brand on filter itself: "ARMA Filtre a.s." based on markings: www.armafiltre.com.tr/uygulamalar/7/3/en/Home-Appliances.html Cannot find any model on website however... looks like Elica's B2B supplier only.

Marker inside after removing filter: 12NC: 208298104403 Model: CIAK GR/A/56.

2018: noticed that it was unbearably greasy, tried to clean, but even boiling water didn't help.

July 2019 message:

Kitchen: 2021-04: nine-volt battery battery at 8.79V. Not sounding.

Unified all previous electro-magnetism theories into one equation.

Explains the propagation of light as a wave, and matches the previously known relationship between the speed of light and electromagnetic constants.

The equations are a limit case of the more complete quantum electrodynamics, and unlike that more general theory account for the quantization of photon.

The equations are a system of partial differential equation.

The system consists of 6 unknown functions that map 4 variables: time t and the x, y and z positions in space, to a real number:and two known input functions:

Due to the conservation of charge however, those input functions have the following restriction:

Also consider the following cases:

The goal of finding $\overrightarrow{\mathbf{E}}$ and $\overrightarrow{\mathbf{B}}$ is that those fields allow us to determine the force that gets applied to a charge via the Equation "Lorentz force", and then to find the force we just need to integrate over the entire body.

Finally, now that we have defined all terms involved in the Maxwell equations, let's see the equations:

You should also review the intuitive interpretation of divergence and curl.

TODO it would be awesome if we could de-generalize the equations in 2D and do a JavaScript demo of it!

Not sure it is possible though because the curl appears in the equations:

Ciro Santilli had to see this in a few separate places, until he underestood: that little pictur emust be a thing! Examples:

Similar to: www.miele.co.uk/e/cylinder-vacuum-cleaner-compact-c2-powerline-sdrf4-10931670-p but slightly different from image. Indistinguishable from: www.currys.co.uk/gbuk/home-appliances/floorcare/vacuum-cleaners/miele-complete-c2-pure-power-powerline-cylinder-vacuum-cleaner-graphite-grey-10208570-pdt.html

Power symbol meanings: images-eu.ssl-images-amazon.com/images/I/A14OZ5TuwGS.pdf

2020-12: buying Miele SF AP 50 AirClean Plus filter www.miele.co.uk/e/airclean-plus-filter-sf-ap-50-10107860-p. Once it arrived, changed the filter, which fit comes with plastic casing and accordion shaped filter. Also changed bag. But the bag full meter still goes to red on carpet even with everything new while vacuuming. Is it supposed to be checked while not vacuuming?

Board LED does not turn on (turned on on first plug, Ethernet always turns on):

Now just HDMI does not work. Possibly a monitor vs television problem:

Manual: images-eu.ssl-images-amazon.com/images/I/D1It8ZCrjLS.pdf

Bought: 2022.

To remove pedals when they get stiff.

Bought: 2020-10.