Ray Lee

Culture is kept in our conversations, for some loose definition of 'conversation'. Black lives matter.

I work in software with a team of physicists, MEs, EEs, and software engineers, all working to protect the biosphere.

I have a background in physics and math to the BSc level. My posts tend to be a mélange of all the above, and a bit more.

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Last Notes

2026-03-04 05:57:07 UTC

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Oh to be a fly on the wall when someone said “Sure, we can measure that. I just need to hike the Pyranees, Andes, and the Tibetan highlands.”
I’m also gratified to hear women involved were acknowledged for their work. The 1940s were more civilized than I thought.
@npub18zu…xdht

2026-03-04 02:00:42 UTC

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I never knew the social impact the calculation had. In class I was too busy saying “Wait, really?”
@npub18zu…xdht

2026-03-03 20:51:30 UTC

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nope. Blame quantum. The amount of time it takes to emit a bit of energy goes as h / delta Energy, with h being Planck’s constant. (More technically, the amount of time it takes to transition between two energy states.) Nature’s granularity strikes again.
Sorry about your hand. Hopefully you don’t have to type much today.

2026-02-12 02:16:00 UTC

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I agree. And I'm pretty sure he'd agree with you, too. I'm doing both you and he a disservice by not sharing the larger context of the conversation. I think his point, which I am expressing poorly, was to try to hold a boundary: Can the evidence be doubted, are there loop-holes in the method or model? etc. He was trying to make me a little more skeptical, which I needed at the time.

2026-02-12 01:48:19 UTC

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My GR professor wouldn't let me use binary pulsars as evidence for gravitational waves in polite conversation, because it wasn't a direct observation. I replied "But what else _could_ it be?" He smiled, shook his head a little, and wandered off.
Anyway, it is an astonishing engineering triumph indeed.

2026-02-12 01:32:23 UTC

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Now that I’m not shooting from the hip, I think I like your suggestion of participants better. Otherwise I’d be implying a load of baggage that comes from the actor model.

2026-02-12 00:24:26 UTC

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actors

2026-02-11 16:03:58 UTC

RE: https://scicomm.xyz/@LIGO/116051346507662792
Happy 10th anniversary to evidence that space is jiggly!
I’m oversimplifying, of course. It’s actually that spacetime is jiggly.

2025-12-02 05:33:32 UTC

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Do you mean compared to what came before? Arguably, GR is the simplest possible thing which could work*. In a sense which @npub1nf4…nqe4 would be able to explain far better than I.
* Except for maybe the cosmological constant term.

2025-10-16 21:49:39 UTC

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Ah, some of that will be right-sized, some will be out of reach then. But I’ll enjoy following along, at least, for the parts where I lack the tools. Congrats on the paper.

2025-10-16 16:26:37 UTC

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I've been looking forward to working through this series over at your blog. Might be a while through. Regardless, thanks for writing a series that's a nice "right-sized challenge" for my skills.

2025-09-06 23:58:01 UTC

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I always enjoy sharing stories of the humorous foibles of life. Politeness prevents me from sharing any about others, but luckily that still leaves me with plenty of material.
As for Einstein and the balloon, I dunno. I'd guess he would be amused but not be fooled by my cheap parlor trick. After he pinned inertial and gravitational mass together, it becomes difficult for me to think of ways around that. The balloon still has real atoms with real mass, so gravity must respond to the mass's energy. The accidental relativity of mass in Newton's equations doesn't carry over, as far as I can see.
By the way, after reading through a few other replies and poking at a couple of Wikipedia articles, I gather the imaginary part of the mass of various fields should be thought as more of a decay rate of unstable particles. Thus Gravity is excused from having to be extended to respond to the imaginary portion directly.
Keeping in mind my formal studies ended after the Bachelor level, is that a fair statement? Does imaginary mass pop up in any other guises other than a decay?

2025-09-05 04:56:33 UTC

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Note to self: Either don't try to talk Physics at 4am, or ensure you make sign errors in pairs.
My bad. Negative mass hurts my head.

2025-09-04 11:55:48 UTC

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I don’t mean to suggest this has any bearing on the possibility of negative mass neutrinos, btw. Your post just reminded me of this, and it’s fun to think about.

2025-09-04 11:30:02 UTC

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One time I was driving with a bunch of helium balloons in the passenger seat to my right. I took a left-hand turn and was surprised when I got attacked by a swarm of party balloons, seemingly accelerating into the turn. It took me a while to realize that all the air heavier than the helium was sloshing to the right, pushing the balloons out of the way and into my head.
There’s a cute paper* that models this by exploiting an accidental symmetry of Newton’s laws. If we arbitrarily consider the air in the car to have zero mass, then the helium balloons must have negative mass, and the dynamics are simpler to model. For example, gravity’s F=mg with negative mass immediately shows the balloons feel a force upward. But it’s just a conceptual simplification. The results are, of course, the same as if we used the actual masses of air and helium everywhere.
As Relativity and QM bring more constraints on mass than Newton has, I don’t think the model carries over to neutrinos. (Like, what would a negative wavelength even mean?) But for balloons, at least, it’s fun to think about. And your post reminded me of it.
Anyway, if the paper had been written a few years earlier, I would have been less surprised. And put the balloons in the back seat.
* https://pubs.aip.org/aapt/ajp/article/82/10/997/1039402/The-concept-of-negative-mass-and-its-application

2025-09-01 04:03:35 UTC

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It certainly is one of the pleasures. And one of the ways I can continue to stretch my skills. But yes, mostly at this point I’d like them to be done, one way or another. I spent a little time this weekend putting boundaries around two of them. One is as done as it needs to be; it taught me what it can. Another might be complete enough, after some callouts of gaps, and some work to exercise the machinery. That may only take a hundred hours. The third… I may just recategorize as an art project.
Regardless, it’ll be nice to get the brain space back, so I can pick up some new hobbies.

2025-08-30 20:21:59 UTC

TFW you have a bit of free time so dust off a hobby project, only to remember it’s actually three hobby projects in a trench coat.

2025-07-13 10:23:11 UTC

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When I got to the part where we (humans) installed a gigawatt of solar power generation every 8 hours in May I had to smile. As so many social ills are tied to fossil fuels, it’s heart warming to see market forces will help defund petrofascism.

2025-07-11 05:10:03 UTC

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Agreed. A favorite lesson I try to remember is about leaving people, or things, better than I found them. Not that I’m any good at it, mind you. But I do think, metaphorically speaking, every step we take can cause flowers to bloom.

2025-07-10 10:46:41 UTC

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We are a surprisingly narcissistic species.
@npub1p7u…kglz

2025-07-10 10:35:53 UTC

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I recently added “After the Spike: Population, Progress, and the Case for People” to my reading queue but probably won’t be getting to it any time soon. See linked post for a short endorsement:
https://fed.brid.gy/r/https://bsky.app/profile/did:plc:o72ypk5c474zqklkukaphuy3/post/3ltho2o57nk22
I tend to think we’re way overpopulated with humans, especially given all our coming challenges with climate change. I figure reading a contrary point of view will be good for me.
@npub1p7u…kglz

2025-06-02 23:22:16 UTC

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Are the schematics online somewhere as well?

2025-06-01 01:51:25 UTC

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I’d be happy to write all the software support, as long as I can waggle all the right pins ftom the cpu.

2025-05-31 22:03:57 UTC

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If you respin the board I’d request a method to program the FPGA without external hardware. I’m used to just loading up new bitstreams on demand, y’know?

2025-05-14 14:53:53 UTC

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Yeah, that seems possible too. So what are all the things which could be going on here?
Thinking out loud, at the interface we have:
- net positivity on the upswing side, as you point out
- differing net velocities of the droplet's sides w/r/t the electron rain
- viscous drag at the boundary with the oil
Outside the interface, the oil feels a field from the static charge on the disk in motion, like a current loop. So there's an induced magnetic field perpendicular to the rotation, which then let's us include the Lorentz force on the electron rain near the boundary.
...that's all I'm coming up with pre-coffee. I'll go poke at references later. Thanks for the puzzle 🙂

2025-05-14 05:06:32 UTC

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I spent a few minutes trying to come up with fancy reasons involving the rotating sphere being a dipole and the induced field somehow causing electrons to prefer to attach to the downward moving side. I failed.
But I think it might be simpler than that. The side moving upward into the electron rain has a higher net velocity with respect to an electron, compared to the side moving downward. It’s going to be harder to stick to something moving faster. The fast side is more likely to kick it away.
The side moving with less net speed is less likely to impart kinetic energy that’s higher than the binding potential energy, which increases the chance for the electron to stick.
Or so I think at the moment. I reserve the right to change my mind and decide this effect is too small to matter in the light of the morning, after a cup of coffee.

2025-05-04 07:33:15 UTC

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contemplating your inbox gives me a mild bit of anxiety. Perhaps we can ask an LLM to apply your crackpot index scorecard to the emails and respond to them for you.

2025-05-03 23:03:24 UTC

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Given the Hamiltonian in QM pushes the state through time, and the Lagrangian is also an energy (therefore, in QM at least, should also evolve something through time, I think?), can we consider the Lagrangian being the evolution of the state function in some lower-energy view? Like maybe the particle's rest frame, rather than something fixed and more global?
I never was able to get a feel for the action in classical mechanics, other than it was formally true and made solving a lot of wacky problems way easier. So thanks for the pointer to the Hamilton-Jacobi equation. I like that Schrödinger's equation can sorta be viewed as the diffusion equation with a phase tossed in, so it's interesting and surprising that there's an analogue in classical mechanics. (Maybe I was absent from class that day.)
@npub1x78…xn0m @npub1glg…tqzy

2025-04-29 03:51:20 UTC

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I regret that I pulled the ripcord on my mathematics education before getting a grounding in all the modern basics. In hopes of getting corrected by you or one of our mutuals, I will display my ignorance.
In software we have this idea of defining how operators act before using them. Equality can be defined a lot of different ways, y'know? One can define in code what the equal sign should mean, depending on the arguments provided -- its context.
Does this overlap with what Noether is saying here? Or is she pointing somewhere else?

2025-04-05 21:28:59 UTC

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I'm glad the first few pages of that were history. That way, <grin>, I can say I made it through the first few pages of that.
His optimism that the path would be fruitful is interesting. Though if discovering deeper truths lies down that path I will content myself being an armchair observer and admiring the work from a distance.
@npub1vlc…mzqq

2025-04-03 01:44:10 UTC

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If you’d written it you would have chosen something other than a running constant for the gag 😉 @npub1vlc…mzqq

2025-03-25 06:22:46 UTC

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As you mention, due to the timing I’ve only seen snow coming southbound. I’ve also done the drive a few times and yeah, a roomette to sleep in is much more civilized. Regardless, I loved learning a bit of both Portland and Seattle. Here’s hoping you two enjoy exploring them if you go.
Given you two lived overseas for a while I thought her Doctorate was in something Chinese related. Are her studies of Navajo weaving personal, or professional? (I’m just curious.)

2025-03-24 04:21:41 UTC

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I’ve taken the coast starlight leg from here (San Luis Obispo) north to Seattle and back a few times. In winter there’s some lovely snowy landscapes in Oregon worth admiring. Sometime I want to take the southern route to admire all the ocean views you can’t see any other way. Trains are great.

2025-03-24 04:08:42 UTC

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I heard the train pass through town today. Had I known you were on it I would have given a cheery wave in that direction. Have fun at your mathematical shindig :-)

2025-02-07 04:27:49 UTC

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I don’t remember if I ever caught them leaving the water running, but that doesn’t surprise me. Water wasn’t billed, and they had no cultural education or care around conservation topics. Water was centrally heated in the two regions I was in. Come springtime the cities turned the hot water off to save money. That’s when we learned it was hard to get soap to lather with ice cold water. We picked up a couple of immersion heaters and made a bath kit we passed around for the last couple months we were there.
I sometimes think I should go back someday and see what’s changed.

2025-02-07 03:11:55 UTC

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Oh man, that photo.
Kazakhstan was multiple kinds of interesting. After the breakup of the Soviet Union, Kazakhstan was one of the last countries to switch to their own currency. It was beautiful stuff -- gold and silver filigree running through the paper, with pictures of poets and philosophers in bright colors. Unfortunately it cost more to print than it was worth. And they didn't have the technology to print it, so they were relying on another country in Europe somewhere to handle that for them.
Like Russia back then, KZ was a totally cash based economy. So to switch the currency, officials went door to door, said "I'm from the government, give me your money," (effectively), and people were granted official IOUs that could be redeemed for cash once the new stuff was finished.
Of course, being a new country and all, they couldn't actually pay for the printing. So the group handling that for them stopped printing the cash until KZ paid their bills.
As it was a cash based economy and they had no cash, everything ground to a halt. Factories couldn't pay workers. They reverted to barter.
A company down in Santa Maria where I was living at the time was selling mining equipment to KZ. They stopped getting paid as well, so once the whole story came out, they said "You know what you need? A debit card system."
I and a handful of others went there to build a system for them. We set it up in a few key factory towns, and trained them on the system for deploying it more widely. Which means I ended up seeing the inside of a lot of banks.
I have a bunch of stories which I should probably write up some time. But for now, a picture of my debit card I had with our system over there.
https://media.mathstodon.xyz/media_attachments/files/113/960/374/275/904/198/original/93f3199fdc550aa6.png

2025-02-05 19:35:38 UTC

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I lived and worked in Kazakhstan for 7 months back in November of '93 through mid '94. (I took a leave of absence from my undergrad program to do it.)
One of our translators, Olga, wistfully spoke of how her family used to vacation along the Aral Sea when she was a child in the early '80s, but it had changed so much by '94 they never went back.
This is good news. I'm glad the current government is doing a bit of caretaking to help restore what was lost.

2025-01-30 03:36:25 UTC

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Agreed. Picking one example a day and ignoring the rest is something easier to crowdsource. And likely easier on everyone so that we all don’t have to track all the chaos. A few minutes online today gave me another example.

2025-01-29 16:40:52 UTC

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I liked this from a former Obama speechwriter: https://contrarian.substack.com/p/how-to-drink-from-a-firehose
It’s on effective communication when talking with people who aren’t keeping up with everything, or think that Trump doing lots of terrible things makes him strong.

2025-01-28 00:58:21 UTC

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As a guess I suspect the image has been gamma corrected. You could try undoing that first. @npub1x78…xn0m

2025-01-04 23:06:37 UTC

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And a happy 1⁰+2⁰+3⁰+⋯+2025⁰ to you, too!

2024-12-03 04:44:51 UTC

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Perhaps for the Third Coming we could try narrowing the gyre instead

2024-12-03 00:31:58 UTC

More evidence space is jiggly!
Pulsars are incredibly precise time keepers. They’re as heavy as stars and spinning, so changing their rotation rate isn’t something that happens quickly, unless something cosmic intervenes.
If they do change their periods temporarily, that’s evidence for gravitational waves rattling around our cosmos, stretching or shortening the signals we receive from them. If you watch enough pulsars for long enough, we can turn our entire galaxy into one big gravitational wave detector!
Which, naturally, people have done. The MeerKAT Pulsar Timing Array team has announced evidence for this “Gravitational Wave Background”. This supports results from other teams announced last year.
Article by @npub169c…jap3 at the link.
https://www.spaceaustralia.com/feature/mpta-finds-evidence-gravitational-wave-background
https://media.mathstodon.xyz/media_attachments/files/113/586/071/629/458/313/original/596d29a64c54ed38.jpeg

2024-11-27 09:08:55 UTC

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I think I have 30TB lying around my house. As storage has gotten much cheaper over the past eight years, distributing copies now seems practical.
@npub1rjk…slfm @npub1nf4…nqe4

2024-11-23 02:38:50 UTC

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Your personal clock is only a tiny bit redshifted from the things closer to the boundary. In your personal coordinate system, and theirs, things are happily passing through the boundary.
Which is to say, I thought this is merely a coordinate singularity, no?
@npub1nf4…nqe4 @npub1hnp…26ht [@j_bertolotti](https://mathstodon.xyz/@j_bertolotti )

2024-11-08 01:15:06 UTC

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Perhaps for the best. Given the lighter gravity I'd bounce off a wave and get bored waiting to come back down again. It'd be easier on my knees, though.
I suppose it's hard to make waves when you're tidally locked to Saturn and have a ~two-week orbit. Per the article, storms seem like an option for creating waves for weathering, but who wants to surf when it's stormy out?

2024-11-07 17:17:30 UTC

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Maybe I'll look into getting some beachfront property on Titan or Europa to weather the changes.

2024-11-01 06:15:09 UTC

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Thanks for posting it here, too. It's always nice to see some forward progress.

2024-11-01 00:13:06 UTC

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It made the news here in San Luis Obispo which is, admittedly, a low bar. Regardless, I was quite happy to see it.
@npub1nf4…nqe4

2024-10-26 22:14:03 UTC

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Thanks for the walkthrough! His example helped me understand my mistake. I was assuming folds were only at the base of each individual triangle. I have a better chance at visualizing it now. Maybe 😅
@npub1fay…s7kh

2024-10-26 15:46:52 UTC

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I enjoyed that essay, thanks for the link!
@npub1vlc…mzqq

2024-10-25 19:30:42 UTC

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I thought I was good at visualizing things but I’m struggling with this one. If we label the external vertices clockwise, starting with 1 for the point at the 12 o’clock position, then I don’t see how it and vertex 3 will ever meet. Vertex 3 seems too short?
Is there perhaps a red line missing at the base of the shape formed by vertices 2, 3, and 4?

2024-10-24 23:58:57 UTC

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To your point, the "god of the gaps" has been a source of motivated reasoning for at least a century if not much longer. Even Newton believed our solar system's structure was due to divine design.
Anywhere science is still fuzzy leaves room for a god, as some argue: https://en.wikipedia.org/wiki/God_of_the_gaps
@npub1nf4…nqe4

2024-09-29 20:57:39 UTC

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An even simpler example, I once wrote a bit of open-source code to compute a 'modular inverse', with comments referencing a paper and a website to read up on limitations of my implementation and faster options.
Out of curiosity, I had GitHub's Co-Pilot write the same function for me. It wrote the exact same code, minus all the helpful comments to help users go learn more.
Citations matter. But that's sometimes counter to the financial incentives of the people who rent time on LLMs, as they may have to flow some of that money (and attention) back to the people who created the training data.
@npub1nf4…nqe4 [@bstacey](https://icosahedron.website/@bstacey )

2024-09-22 19:44:45 UTC

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Progressive scratchpad collapse is the name of my next b̶a̶n̶d̶ notebook.
@npub1nf4…nqe4

2024-08-24 16:02:19 UTC

I like it.
https://media.mathstodon.xyz/media_attachments/files/113/017/828/366/940/674/original/df18038141cd5f4b.png

2024-08-14 01:08:04 UTC

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I’m eyeing fuzix as an option https://github.com/EtchedPixels/FUZIX

2024-08-13 18:23:34 UTC

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Graphics Adapter for Retropixel Yeeting

2024-08-13 18:00:38 UTC

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The Jay Miner designs (Atari 8-bit and Amiga) used display lists. See, for example, https://www.atariarchives.org/dere/chapt02.php . The Antic (Atari) and Copper (Amiga) coprocessors are the ones that interpret the tiny instruction sets for waits, moves, and branches.
[@mos_8502](https://studio8502.ca/@mos_8502 )

2024-08-13 17:46:37 UTC

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while we’re asking for ponies, an 8-bit era trick is reprogramming the palette on the fly to exceed the maximum number of colors per frame.
Another pony would be a way to make ‘display lists’ for arbitrary mappings for starts of scan lines in memory. This allows smooth scrolling of a field, for example, without much cpu overhead.
Just thoughts, feel free to ignore!
[@mos_8502](https://studio8502.ca/@mos_8502 )