Inkscape is a a good software for editing/creating SVG files.
Its functionality is fundamental for as a software for drawing geometry diagrams, as it is a good middle ground between algorithmic generation, and raster graphics.
At 1.0.2, its UI is a bit terrible:
- the way the menus open on the right with title below the window...
- several defaults are atrocious, e.g. export drawing rather than page
And it crashes from time to time on Ubuntu 21.04. And it has some glaring bugs, e.g.:
But still, it is a very good initiative.
What would be really amazing is if they had constraints: gitlab.com/inkscape/inbox/-/issues/1465 like proper CAD software, it would make it possible to not have to redo entire diagrams when you want to change a small part of them.
The IBM 1401 compiles and runs Fortran II by CuriousMarc (2018)
Source. Allows us to draw with JavaScript pixel by pixel! Great way to create computational physics demos!
Here is an animation demo with some useful controls:
HTML snippet:
new class extends OurbigbookCanvasDemo {
init() {
super.init('hello');
this.pixel_size_input = this.addInputAfterEnable(
'Pixel size',
{
'min': 1,
'type': 'number',
'value': 1,
}
);
}
draw() {
var pixel_size = parseInt(this.pixel_size_input.value);
for (var x = 0; x < this.width; x += pixel_size) {
for (var y = 0; y < this.height; y += pixel_size) {
var b = ((1.0 + Math.sin(this.time * Math.PI / 16)) / 2.0);
this.ctx.fillStyle =
'rgba(' +
(x / this.width) * 255 + ',' +
(y / this.height) * 255 + ',' +
b * 255 +
',255)'
;
this.ctx.fillRect(x, y, pixel_size, pixel_size);
}
}
}
} Hertz electromagnetic wave experiments by 
Ciro Santilli 35 Updated 2025-01-10 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-01-10 +Created 1970-01-01Heinrich Hertz's main initial experiment used a spark-gap transmitter. It is not something that transmits recorded sounds like voice: it only transmits noisy beeps. And as such was used for wireless telegraphy.
Hertz Experiment on Electromagnetic Waves by Ludic Science (2015)
Source. Simplified recreation with cheap modern equipment. Uses as transmitter power source both:- a piezo igniter from a barbequeue lighter
- a more powerful home-made transformer
Hertz and Radio waves Explained by PhysicsHigh (2016)
Source. Simple schematics showing the basics of the experiments. No choice of components rationale.Correspond to the angular part of Laplace's equation in spherical coordinates after using separation of variables as shown at: en.wikipedia.org/wiki/Spherical_harmonics#Laplace's_spherical_harmonics
Notable examples:
Structure of a Gram-negative bacteria
. Source. 
Trying to use gallium arsenide was Seymour Cray's fatal last flaw as mentioned at The Supermen: The Story of Seymour Cray by Charles J. Murray (1997).
The Supermen: The Story of Seymour Cray by Charles J. Murray (1997) page 4 mentions:
Cray wanted his new machine to employ circuits made from a material called gallium arsenide. Gallium arsenide had achieved limited success, particularly in satellite communications and military electronics. But no one had succeeded with it in anything so complicated as a computer. In the computer industry, engineers had developed a saying: "Gallium arsenide is the technology of the future," they would say. "And it always will be."
Their split in 1970 was a huge fuck up. If it were a single entity, the university would likely be in the top 10 university rankings, undoubtedly top 20. But as of 2020 French universities only appear instead in the top 40s or 50s.
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