mgsouth (u/mgsouth) - Readit News

mgsouth commented on Synology Lost the Plot with Hard Drive Locking Move servethehome.com/synology... · Posted by u/motiejus

mgsouth · 8 months ago

I've no experience with Synology and have no opinion regarding their motivations, execution, or handling of customers.

However...

Long long ago I worked for a major NAS vendor. We had customers with huge NAS farms [1] and extremely valuable data. We were, I imagine, very exposed from a reputation or even legal standpoint. Drive testing and certification was A Very Big Deal. Our test suites frequently found fatal firmware bugs, and we had to very closely track the fw versions in customer installations. From a purely technical viewpoint there's no way we wanted customers to bring their own drives.

[1] Some monster servers had tripple-digit GBs of storage, or even a TB! (#getoffmylawn)

mgsouth commented on Vibe Coding in Common Lisp funcall.blogspot.com/2025... · Posted by u/mgsouth

mgsouth · 9 months ago

One man's ongoing journey coaxing an LLM to write Common Lisp code. Bonus "AI generated" poem by Stanislaw Lem, and a five-paragraph story actually generated by LLM: "The Unspeakable Syntax: A Tale of Lispian Horror." [3] Suprisingly entertaining.

Posts so far:

[1] https://funcall.blogspot.com/2025/03/vibe-coding-in-common-l...

[2] https://funcall.blogspot.com/2025/03/vibe-coding-in-common-l...

[3] https://funcall.blogspot.com/2025/03/ai-silliness.html

[4] https://funcall.blogspot.com/2025/03/vibed-into-non-function...

mgsouth commented on Why some DVLA digital services don't work at night dafyddvaughan.uk/blog/202... · Posted by u/edent

mjevans · a year ago

There might be legal / compliance reasons. It can be incredibly difficult to replace a validated system that is known (or already accepted even if it's technically incorrect) to implement lawmaker dictated behavior.

Otherwise, I think a new approach might be to ignore the specifics of the old system, implement a new system, and a separate translation layer that can run on an export of the old system (or the old system brought back online, but read only after the overnight maintenance) and completely cut over during an otherwise holiday weekend.

mgsouth · a year ago

    > I think a new approach might be to ignore the specifics of the old system, implement a new system

It doesn't work like that. When you're revamping large, important, fingers-in-everything-and-everybody's-fingers-in-it systems you can't ignore anything. A (presumably) hypothetical example is sorting names. Simple, right? You just plop an ORDER-BY in the SQL, or call a library function. Except for a few niggling details:

1. This is an old IBM COBOL system. That means EBCDIC, not UTF or even ASCII.

1.A Fine, we'll mass-convert all the old data from EBCDIC to UTF. Done.

1.A.1 Which EBCDIC character set? There are multiple variants. Often based on nationality. Which ones are in use? Can you depend on all records in a dataset using the same one (hint: no.) Can you depend on all fields in a particular record using the same one? (hint: no.) Can you depend on all records using the same one for a particular field? (hint...) Can you depend on any sane method for figuring out what a particular field in a particular record in a particular dataset is using? Nope nope nope.

1.A.2 Looking at program A, you find it reads data from source B and merges it with source C. Source B, once upon a time, was from a region with lots of French names, and used code page 279 ('94 French). Except for those using 274 (old Belgium). And one really ancient set of data with what appears to be a custom code set only used by two parishes. Program A muddles through well enough to match up names with C, at least well enough for programs D, E, and F.

1.A.3 But it's not good enough for program G (when handling the Wednesday set of batches). G has to cross-reference the broken output from A with H to figure out what's what.

1.B You have now changed the output. It works for D and F, but now E is broken, and all the adhoc, painstakingly hand-crafted workarounds in G are completely clueless.

1.C Oh, and there's consumer J that wasn't properly documented, you don't know exists, and handles renewals for 60-70 year old pensioners who will be very vocal when their licenses are bungled.

2. Speaking of birth years, here's a mishmash of 2-, 4-, and even 3-digit years....

mgsouth commented on Supernovae evidence for foundational change to cosmological models academic.oup.com/mnrasl/a... · Posted by u/JumpCrisscross

le-mark · a year ago

As a layman, what I don’t get is; the speed of light is constant, so wouldn’t that nullify any time/space fluctuations due to lack of mass/gravity?

mgsouth · a year ago

As another layman, no, I don't think so.

The "twin paradox" [1] is a prime example. The two twins depart from a common point in time and space, go about their separate travels, and meet again at a common point in space-time. Despite both twins always having the same constant speed of light, one of the twins takes a shorter path through time to get to the meeting point--one twin aged less than the other. In the paradox case, the shorter/longer paths are due to differences in acceleration. But the same thing happens due to differences in gravitation along two paths. (In fact, IIUC, acceleration and gravitational differences are the same thing.)

Just thinking about the math makes my head hurt, but it's apparent that two different photons can have taken very different journeys to reach us. For example, the universe was much denser in the dim past. Old, highly red-shifted photons have spent a lot of time slogging through higher gravitational fields. As a layman, that would suggest to me that, on average, time would have.. moved slower for them?... they would be even older than naive appearances suggest. I don't think the actual experts are naive, so that's been accounted for, or there's confounding factors. But I could also imagine that more chaotic differences, such as supernovas in denser galatic centers vs. the suburbs, or from galaxies embedded in huge filaments, could be hard to calculate.

[1] https://en.wikipedia.org/wiki/Twin_paradox

mgsouth commented on macOS menu bar app that shows how full the ISS urine tank is in real time github.com/Jaennaet/pISSS... · Posted by u/ajdude

kylecazar · a year ago

More agile

mgsouth · a year ago

You don't really want an agile toilet interface. This is more a waterfall project.

mgsouth commented on Using GPS satellites to detect tsunamis via ionospheric ionization waves earthdata.nasa.gov/learn/... · Posted by u/Gedxx

mgsouth · a year ago

Pretty astounding, isn't it? I don't see a paper, but there was a webinar [1]. There's a technical synopsis at 8:00. The phenomenon they're measuring is actually signficant. It's the total number of (free?) electrons between the satellite and the receiver. Typically its about 10^12 electrons/m^3 (@8:00 in video). The disturbance from the 2011 earthquake and tsunami was, if I'm reading the movie/chart correctly, about +/- 1 TECU, which is 10^16 electrons/m^3 (@10:40). The water elevation may only be a few feet in open ocean, but it's over a vast area. That's a lot of power.

They're measuring it by looking for phase differences in the received L-band (~2GHz) signals, rather than amplitude. That eliminates lots of noise. And they're looking for a particular pattern, which lets you get way below the noise floor. For example, the signal strength of the GNSS (GPS) signal itself might be -125 dBm, while the noise level is -110 dBm [2]. That means the signal is 10^-12 _milliwatts_, and the noise is about 30 times larger. But by looking for a pattern the receiver gets a 43 dB processing boost, putting the effective signal well above the noise.

[1] https://www.youtube.com/watch?v=BEpZmRPPWFo

[2] https://www.nxp.com/docs/en/brochure/75016740.pdf

mgsouth · a year ago

OK, the "typically 10^12 TEC" vs. a +/- 1 TECU (10^16 TEC) disturbance was really bugging me. I think the slide has an error, or there's an apples/oranges issue. The +/- 1 TECU looks to be consistent, but the typical background level is "a few TECU to several hundred" [1]. A Wikipedia page has shows the levels over the US being between 10 - 50 TECU on 2023-11-24, and says that "very small disturbances of 0.1 - 0.5 TEC units" are "primarily generated by gravity waves propagating upward from lower atmosphere." [2].

[1] https://www.swpc.noaa.gov/phenomena/total-electron-content

[2] https://en.wikipedia.org/wiki/Total_electron_content

mgsouth commented on Using GPS satellites to detect tsunamis via ionospheric ionization waves earthdata.nasa.gov/learn/... · Posted by u/Gedxx

unsnap_biceps · a year ago

This is amazing work. I don't quite understand how they are detecting the tsunamis though. They mention that this works via significant displacements of air. Is the amount of air displacement in the open ocean statistically significant for detection or is it being detected via a slightly different source.

mgsouth · a year ago

Pretty astounding, isn't it? I don't see a paper, but there was a webinar [1]. There's a technical synopsis at 8:00. The phenomenon they're measuring is actually signficant. It's the total number of (free?) electrons between the satellite and the receiver. Typically its about 10^12 electrons/m^3 (@8:00 in video). The disturbance from the 2011 earthquake and tsunami was, if I'm reading the movie/chart correctly, about +/- 1 TECU, which is 10^16 electrons/m^3 (@10:40). The water elevation may only be a few feet in open ocean, but it's over a vast area. That's a lot of power.

They're measuring it by looking for phase differences in the received L-band (~2GHz) signals, rather than amplitude. That eliminates lots of noise. And they're looking for a particular pattern, which lets you get way below the noise floor. For example, the signal strength of the GNSS (GPS) signal itself might be -125 dBm, while the noise level is -110 dBm [2]. That means the signal is 10^-12 _milliwatts_, and the noise is about 30 times larger. But by looking for a pattern the receiver gets a 43 dB processing boost, putting the effective signal well above the noise.

[1] https://www.youtube.com/watch?v=BEpZmRPPWFo

[2] https://www.nxp.com/docs/en/brochure/75016740.pdf