@dpiponi@mathstodon.xyz
@dpiponi@mathstodon.xyz avatar

dpiponi

@dpiponi@mathstodon.xyz

Disclaimer:
👽 My opinions are not my own. They're beamed to me by aliens

Current life:
🎮 Epic Games

Previous lives:
🍩 a PhD in Riemann theta functions
💥 many years working in movie visual effects
🎈 some years devising navigation strategies for balloons
🎲 a year drawing random samples from tricky distributions

Likes:
🚴 I like to bike
🏃 I like to run
🎛️ my musical tastes lie towards the electronic end of the spectrum
🚀 I like Andor and The Mandalorian

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dpiponi, to random
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Too much of my life spent wrangling build systems rather than writing actual software that does something.

dpiponi,
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@SvenGeier You mean add even more clutter to the build wrangling ecosystem? :)

dpiponi, to random
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Looks like the Google Chart API has dropped its support for latex expressions (or it's temporarily out of action) which means my blog is now packed solid full of broken links. I did start the process of making more stable versions of some of the articles as PDFs here: https://github.com/dpiponi/StableBlog Luckily I wrote a lot of that stuff with my own homebrew markup that can be translated to LaTeX somewhat mechanically.

dpiponi,
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@BartoszMilewski That's actually what I have! Using Parsec too. It's such an abomination I started modifying the 'language' to make it easier for Parsec. And that's why I call it markup rather than LaTeX. (Eg. LaTeX uses $ for opening and closing math expressions which can be a nightmare in a backtracking parser.)

dpiponi,
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@theohonohan @dingc @christianp I originally considered Jax but at the time it required an external dependency I trusted less than Google. My mistake :)

johncarlosbaez, (edited ) to random
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So you wake up one day wanting to invent a 2-dimensional number system. This requires a new number 𝑖 that's at right angles to 1. So you figure multiplying by 𝑖 must rotate numbers by 90°. So multiplying by 𝑖² rotates by 180°, so

𝑖² = -1

Cool!

Then you notice something else. The derivative of a function in the 𝑦 direction must be 𝑖 times its derivative in the 𝑥 direction, because the derivative is linear and you get the 𝑦 direction by rotating the 𝑥 direction by 90°: that is, multiplying it by 𝑖. So you get this equation:

[ \frac{\partial f}{\partial y} = i \frac{\partial f}{\partial x} ]

Cool!

Then you notice something else. If you use this equation twice you get

[ \frac{\partial^2 f}{\partial y^2} = i \frac{\partial f}{\partial x\partial y} = i^2 \frac{\partial^2 f}{\partial x^2} = - \frac{\partial^2 f}{\partial x^2} ]

so

[ \frac{\partial^2 f}{\partial x^2} + \frac{\partial^2 f}{\partial y^2} = 0 ]

Wow! Every function with a second derivative obeys the Laplace equation!

You decide this one is a keeper.

https://en.wikipedia.org/wiki/Cauchy%E2%80%93Riemann_equations

dpiponi,
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@mattmcirvin @johncarlosbaez Same here. I hope to get to the bottom of it one day.

dpiponi,
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@johncarlosbaez @mattmcirvin For me the amazing things happen in applications when you you feel like you're apparently getting something for nothing: eg. in quantum mechanics, optics, signal processing. Here differentiability is closely related to causality (maybe that's connected to your split complex example, not sure) and so if you say certain quantities are differentiable you may actually be making a strong statement about the underlying physics.

dpiponi, to random
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TIL about mouse jigglers

https://www.amazon.com/s?k=mouse+jiggler

dpiponi,
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@gregeganSF The latter judging by the reviews

dpiponi,
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@BartoszMilewski Sad :(

dpiponi, to random
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Stupidity knows no bounds. Apple Preview has a "redact" facility. Despite the fact that Preview renders the text, and so obviously knows the bounding box of the text you're redacting, it still leaves the top and bottom of the text visible making it fairly easy to reconstruct.

There's a certain class of bug that ought to have its own name: it's the completely obvious bug that just about anyone but a software engineer could anticipate so you have to test the software first make sure it doesn't have the bug.

dpiponi,
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@BartoszMilewski In the case of Apple I think aesthetics is trumping usability. Things like insisting on animating everything even though the times to play animations are long compared to the time it takes for experienced users to move from one thing to the next.

I also wonder if there are some tricky challenges associated with writing asynchronous UI code because to me it feels like some of the annoying things are about asynchronicity.

dpiponi,
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@BartoszMilewski As an example of asynchronicity: I've skipped a heartbeat a couple of times when I've been told my bank balance is zero. The UI wants to display something immediately and it renders a default value of zero. A second or two later the real data arrives and the display is updated.

dpiponi,
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@BartoszMilewski Have you ever used iTunes under Windows? It literally crashed as I was about to write this toot. (The content would have been slightly different had it not crashed :)

dpiponi, to random
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I'm astonished by the way user interfaces just keep getting worse and worse.

It used to be that you had buttons and when you clicked on a button there was visual indication that you had clicked. But now buttons have been abandoned. We just have text without any indication that it is a button. And when you click there's no visual indication. And nowadays everything is asynchronous so pressing a button probably has to spin up a new thread that probably has to send your private data somewhere and 3 seconds later there's still no visual indication anything has happened so you click again a dozen more times and you you get a slew of error messages about repeating the same operation and I really miss DOS when pressing a button made something happen and if it took a while there'd be a message saying "working..." within a tenth of a second.

gregeganSF, to random
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Saw someone hyperventilating over LLMs “passing the mirror test”, so …

TL;DR This short program “recognises itself”: show it a file containing its own source code and it will print “This is me!”

Underwhelmed? You should be! But I did have to type a lot of backslashes.

dpiponi,
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@gregeganSF I hyperventilate over the mirror test too - but mostly out of frustration with people taking it seriously - as if somehow a stupid test gets some kind of imprimatur because a bunch of psychologists say it's important. TBH I feel similarly about all that self-awareness business too.

pervognsen, to random
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What is going on here.

dpiponi,
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@pervognsen Old book, no longer in print, various editions are rated differently, and now there's an ebook which isn't rare but many still prefer to buy used on paper.

dpiponi, to random
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Not sure why Christopher Walken was in Dune 2. Why pay big actors to do next to nothing? Instead, watch Outsiders where Walken is absolutely fantastic (along with all the rest of the cast). And Severance. TBH I just got a kick out of him mentioning shopping at Tesco's. A far cry from being Emperor of the Universe.
https://www.imdb.com/title/tt11646832/

dpiponi,
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@BartoszMilewski Yeah. Just corrected it.

dpiponi, to random
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There was that time Vernor Vinge visited us at Google X and tried out Google Glass, the technology he foresaw.

dpiponi, to random
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The clickbaity title of an article in the Cambridge University alumni magazine caught my attention: "Pythagoras was wrong"

The Nature article linked to is good though.

Quick summary: what chords sound consonant or dissonant? Two leading models: one based on the idea of humans liking integer or rational ratios between the frequencies of the partials, and the other based on the idea that humans don't like to hear almost but not quite equal partials "rubbing up" against each other. (The latter model is championed by Sethares whose book on timbre I recommend.) These models have mostly been just talk but this new research tested preferences among many subjects.

Conclusion: sometimes the integer/rational model makes very good predictions and the other model completely fails. And vice versa.

https://www.nature.com/articles/s41467-024-45812-z

dpiponi,
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@scheidegger I love that book and I still think his model is really good despite some negative examples in this paper. This paper has a nice tweak to Sethares' model where they account better for the fact that people do actually like to hear a mixture of very close but unequal frequencies. (Of course they do, that's why we have things like chorus pedals and vocal doubling.)

Not sure where RKHS fits in - the obvious kernel I see is the one for the subjective "roughness" between pairs of frequencies, but I'm not sure how to make an RKHS from that.

dpiponi,
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@scheidegger Ultimately this should be an integral rather than sum over the Fourier domain (or at least small window Fourier transforms). I'd like to see a wider variety of instruments accounted for beyond ones with individual sharp peaks. Eg. Electric guitars with lots of distortion (which still sound pitchy despite what must be a wild spectrum), and wind instruments that sound pleasant despite sounding "breathy" which I think means there's a large noise component with broad peaks in the spectrum. (Based on my attempts to emulate these sounds.)

dpiponi, to random
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I think this must be the question in fundamental physics and someone had to ask it: https://physics.stackexchange.com/questions/806682/how-does-spacetime-curve-around-an-object-in-superposition

The idea that spacetime itself isn't in superposition seems a bit nuts to me - but of course we don't have a working theory of that.

dpiponi,
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@BartoszMilewski That stuff's old - I remember going to a talk on that as an undergrad. I think this all ties into Penrose's idea that brains are large enough, and hence interact with gravity enough, to cause this collapse... 🤪

dpiponi,
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@BartoszMilewski Penrose had an amazing mind and made incredible contributions in a wide variety of areas and if it turns out he was correct in yet another one then he deserves that last laugh!

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