Seeing there's a new Bartosz Ciechanowski explainer might be my one exception to this rule.
The one lesson I learned the hard way is that if you run a full-volume sine wave long enough you can permanently destroy your laptop speakers.
Amazing content as always otherwise.
FWIW the The Scientist and Engineer's Guide doesn't actually cover a lot on sound. It starts in a particular DSP way with frequency domain definitions and convolution - and I actually think Steven's background is in medial imaging, though I could be mistaken.
One thing that surprised me the first time I learned it is how 'dense' air is under normal circumstances. The 'mean free path' is the mean distance that a particle travels before changing velocity (typ due to collision). The mean free path of atmospheric air at standard pressure is ~65 nanometers, with ~2x10^19 (20 billion billion) molecules per cubic centimeter experiencing about 10^33 collisions per second. This is roughly the volume of an adult's ear canal.
This is the type of blog I aspire to make, one day
edit: If I limit Firefox to 60fps (down from my display's 280hz) then it seems to work fine.
They way he is able to explain complex subjects by starting from first principles, gently adding more and more layers, with beautiful, custom-made figures and animations is truly, literally, awesome.
I strongly recommend supporting the author via his Patreon if you enjoy his blog posts.
Isn't 460 m/s the speed of the shock waves?
I mean, it you make some "air particle" move, it'll hit a nearby particle, and so on, and this wave has a speed of 460 m/s. In a solid object (wood, for example) the particles are close together and the speed will be greater. If you remove air particles it'll decrease the pressure and the speed will be slower...
Clicking on the word 'switch' does exactly that. That's a delightful and clever touch that of course comes from Bartosz Ciechanowski.
And it's due to this speed, despite air's low density, the force air exerts is enormous -- equivalent to 10 tons per square meter. Somehow, the human sandwich does not explode nor implode due to equivalent pressure coming from the other side and inside.
Any one of these pages would be a feat, an achievement to be proud of, but as a collection, it forms one of the greatest educational resources of its type that I have known.
These things can give you more intuition about a subject in 45 minutes than a textbook might be able to in 3 months, because it's interesting and not dry.
I wish I had more time to rant about this right now, but I haven't, so: Kudos. Another amazing job.
Several of the piano key demos ask you to observe what happens when you play multiple keys at once. Is there a way to do this on a desktop PC that I am missing? I had to switch to my phone to try those sections.
When I increased the slider that allows you to change the flow of time for the gas in the cube, it really looked like visualizations I've seen of increasing the temperature of a gas. Is there a deeper relationship here? Could an observer tell the difference between a cube $A$ of gas in which the flow rate of time were doubled and a cube $B$ of gas with normal time passage, but a correspondingly increased temperature? If so, what would give it away?
One suggest to Bartosz: breaking one long essay into many smaller pages or hiding content until the viewer has indicated understanding of previous steps will be even more useful (see: https://tigyog.app/d/H7XOvXvC_x/r/goedel-s-first-incompleten...).
Explorable models are a great way to increase engagement and understanding. Beyond that, I would supplement this with highly frequent comprehension questions to check for learning. I bet you'd find a way to make it fun and approachable.
Interesting side note - using the "basic" frequency/amplitude slider section, you can tell if you have any hearing loss in a certain ear at a certain frequency, as well as high frequencies in general.
As an ex-musician, I have some hearing loss caused by playing and being around extremely loud music. Between 6KHz and 7KHz, I felt the sound shift towards my right hear, indicating some hearing loss at that frequency in my left ear. Between 10KHz and 11.5KHz, I felt a strong shift toward my left ear, indicating hearing loss at those frequencies in my right ear. Above about 12.3KHz, I lost the sound entirely.
One very gentle bit of feedback (haha) to the author would be to provide anchors to each section so they could be more easily linked.
On atomic level. Like atoms oscilating? How many photons are emitted when say 5 carbon atoms connect with 5 oxyxen particles? I tried searching and no avail.
All education should aim for this bar
That's kinda crazy to think about. Someone across a gymnasium room farts, and you smell it milliseconds later. Ugh.
Amazing work.
Superb post.
https://blog.fluance.com/wp-content/uploads/2021/05/Ported-V...
Is the hole to help get the sound out..? No. As this article shows you, the speaker already moves back and forth, this will create changes in pressure yada yada.
The speaker port is not just a hole, it’s a tube. The air in that tube has a mass and due to changes of air pressure inside the box, the air mass in the tube will move back and forth just like a plate in the article.
The result is that you basically have 2 “moving plates” which create sound: the speaker cone itself powered by a motor, and the air mass in a tube powered by the air pressure in the speaker enclosure.
Cool video about speaker design
Edit: Oh, I think the answer is 6493 lines of artisanally hand-crafted javascript + WebGl. Beautiful.
This was great.
One of my favorite articles is this one on hex grids: https://www.redblobgames.com/grids/hexagons/ it blew my mind the first time I noticed that all the interactions and code change when you toggle between "flat topped" and "pointy topped".
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