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Sound

ciechanow.ski

201–210 of 222 posts

Re: Sound

#202

Side note. I have always wondered, if we can hear the multiple frequencies caused by wave interference in soundwaves (e.g. square vs sine), why can't we see multiple frequencies in light waves. I assume it's just too fast?

We can, but we lump them into three bins, L, M, and S. The usual red, green, and blue are derived from those. L, M, and S are sensed by different cells.

https://en.m.wikipedia.org/wiki/LMS_color_space

Similarly, our ears are sensitive to a rather larger number of frequency bins, and and each sensory cell senses one of these bins.

Neither of these sensory mechanisms is particularly sensitive to phase and, in fact, we can’t hear phase differences very well.

Re: Sound

#203

Side note. I have always wondered, if we can hear the multiple frequencies caused by wave interference in soundwaves (e.g. square vs sine), why can't we see multiple frequencies in light waves. I assume it's just too fast?

It's more useful in an evolutionary sense to look at a banana and see that it's yellow, than to feel distinctly that your red and green cone cells are each being stimulated separately.

The combination happens in our brain because it's transforming those separate signals into useful information.

Re: Sound

#204
post #132
post #61

Earlier quoted context omitted.

And yet somehow, as far as we know, the energy of every molecular collision is faithfully preserved during a supernova, when effectively the entire volume of a star collapses into its core in less then a second. Reality is very strange.

That's not accurate. Only the inner core collapses (hence the "core-collapse supernova"; there are also other types), the rest rebounds, is heated up by core-produced neutrinos, and gets ejected. The Wikipedia article is a good start, also there are plenty of good papers on arxiv (e.g. on still-not-too-successful numerical modeling of the aforementioned "heating", without which the thing simply doesn't go bang).

Good correction, thank you!

Re: Sound

#205
I took a Physics of Sound class for my minor in Physics during undergrad. One of my favorite classes I've taken.

Re: Sound

#207
post #200

Earlier quoted context omitted.

It’s a few lines of standard JavaScript. Nice touch used by many sites, not difficult.

How is it done? Could you point to the section of code in the source code?

The relevant few lines are these:

    if ("IntersectionObserver" in window) {
        const observer = new IntersectionObserver(entries => {
            entries.forEach(entry => { entry.target.drawer.set_visible(entry.isIntersecting); })
        }, { rootMargin: "300px" })

        all_containers.forEach(container => observer.observe(container));
    } else {
        all_containers.forEach(container => container.drawer.set_visible(true));
    }
You can read more about it here: https://developer.mozilla.org/en-US/docs/Web/API/Intersectio...

As a side note, all of the code is very pleasant to read. It's interesting that it's seemingly (almost) all hand-written, given that there are commented-out rules in the CSS, for example. I'm not sure what's going on with the HTML though, probably some custom generator.

Re: Sound

#208

As an educational psychologist, there's a lot to love here and I catalog posts like these as examples of expert exposition. 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…

Can u share your catalog, i really liked both the op's post and the tigyog.app one. And i am looking for more!

Re: Sound

#209

Bartosz if you’re reading this, please make one about electronic circuits, starting from atoms to CPUs if possible! :)

Not really identical, but I'd recommend the course Nand to Tetris (I believe on YouTube/also some online platforms) and this introduction to assembly - https://github.com/hackclub/some-assembly-required

Re: Sound

#210
For those looking for more interactive content like this, albeit with more of a game dev focus, I highly recommend https://www.redblobgames.com

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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