Matt Ferraro writes long technical posts on physics, math, CNC router design, geometric algebra, and building a browser-based CAD program.
Commenters praise his posts, such as the magic windows physics article and the CNC router guide, and link his CAD and geometric algebra pieces.
Since we're sharing links, here's my collection of interactive pages too:
Interactive visual explanations of math and algorithms, with motivating examples from computer games.
https://www.redblobgames.com/
The world's first linear algebra book with fully interactive figures.
http://immersivemath.com/ila/index.html
The Textbook of the Future. Interactive. Personalised. Free.
https://mathigon.org/
Structure and Interpretation of Computer Programs. Interactive Version
https://xuanji.appspot.com/isicp/
An Interactive Introduction to Fourier Transforms
http://www.jezzamon.com/fourier/index.html
Clear, intuitive lessons about imaginary numbers, exponents, and more.
https://betterexplained.com/
An Interactive Introduction To Quantum Computing
http://davidbkemp.github.io/QuantumComputingArticle/
The website of Martin O'Leary artist, designer, teacher, researcher.
http://mewo2.com/
A Visual and Interactive Guide to the Basics of Neural Networks
https://jalammar.github.io/visual-interactive-guide-basics-neural-networks/
Interactive demos on network theory, game theory, trust etc.
https://ncase.me/
An interactive explanation of curves and surfaces
https://ciechanow.ski/curves-and-surfaces/
Introduction to geometric algebra — an invertible vector product and the implication of having one.
https://mattferraro.dev/posts/geometric-algebra
Interactive visualizations for different topics from physics and mathematics. Includes trigonometry, polynomial regression, and Bézier…
> Joules-Thomson effect is what allows for refrigeration
I don't think this is true. The "simple" model of refrigeration taught in highschool is just a carnot cycle running backwards, and this can be modeled with an ideal gas. The author of the post covers this the section on "the Thermodynamics 101 Answer"[1], where all you need to drop the temperature of a gas is to let it do work on the piston.
That's not to say that JT is not useful, just that we can explain a theoretical refrigerator without it.
[1] https://mattferraro.dev/posts/joule-thomson#the-thermodynamics-101-answer
I love the last section of "Hiding Images in Plain Sight: The Physics Of Magic Windows"[0]
>I know what you're thinking. What about the hologram?!
>Does the math above imply that a hologram will always be created, or is this one cat hologram just an incredible coincidence?
>Well you see, I've discovered a truly marvelous proof of this, which this website's margin is unfortunately too narrow to contain :)
[0]: https://mattferraro.dev/posts/caustics-engineering
More useful is one of his references on how to build a CNC router.[1] This one covers all the usual mistakes one can make building a CNC router.
(He skips the real n00b mistake - trying to use a Dremel tool in a CNC router.
That never works. Dremel tools slow down or stall under load, and the CNC controller doesn't detect that, so it keeps pushing a stalled tool around.)
[1] https://mattferraro.dev/posts/cnc-router
Some other open source 3D CAD tools:
Code-based
- CadQuery - https://github.com/CadQuery/cadquery/
- build123d - https://github.com/gumyr/build123d
- OpenSCAD - https://openscad.cloud/openscad/
GUI (browser-based)
- Cadmium (abandoned, cool idea) - https://mattferraro.dev/posts/cadmium
For people interested in this topic, here's a good set of slides going over Grassman/Clifford/Geometric algebra concepts: http://www.terathon.com/gdc12_lengyel.pdf
And another good site: https://mattferraro.dev/posts/geometric-algebra