If you ever are in Paris, I can't recommend the Musee des Arts et Metiers enough.
I believe they have the several reference platinum kilograms that are now out of spec. [1]
they also have the original actual Foucault pendulum that was used to demonstrate Earth's rotation. (and a replica doing a live demo, of course)
They have so many incredible artifacts (for weights and measures but also so much more: engineering, physics, civil engineering, machining,...)
I don't know if you will be reading this, but I am just back from that museum. Thank you very much for the information.
I spent 4 hours to there and was surprised to see so many tourists, this is not a place I expected people visiting Paris to go to. There were no crowds though.
The top part is really great, you get to see how much people did with so little. So is the chemistry part.
I found the steel replica of the kilogramme and the meter, and of course the Foucault pendulum (in the neighboring refurbished church).
This is truly an interesting museum, on part with the museum of discoveries (musée de la découverte) which is unfortunately close now for a few years for renovations (or at lest was recently planned to be closed). Much better than La Vilette.
Ahhh, thank you for the tip. I live in Versailles and usually go to museums for art, but this would be wonderful as well.
The Musée de Sèvres (or Bureau des Mesures as it is called now) has the original kilogramme and meter iridium reference, hidden in the basement ;( So if the director has a change of heart, I am all in!
On the topic of tricking the automated phone usage detection cameras this youtuber had an entertaining video where he built a car phone holder by molding his hand and making a replica.
I suspect hiding the manufacturer/model was very much on purpose, they blurred the markings on the PCB and hid the domain name for the manufacturer's API calls (and in the console logs as well).
H.I. Sutton did a great video [1] about it that also explains how it was beneficial due to the way enemy submarines had to estimate speed and heading and could get fooled.
When you're trying to hit something moving 20kt, with something moving 30-35kt, from a few thousand yards, it doesn't take much error in estimating speed, heading, or distance, to make them miss. It's honestly more remarkable that they hit at all in those conditions, even with a "spread" (shooting several along slightly different headings hoping one or two will hit).
Anyone with a copy of Silent Hunter 3 https://store.steampowered.com/app/15210/Silent_Hunter_III/ can experience this for themselves. Trying to estimate another ship's heading from a vantage point near sea level is maddening, even with the aid of a little recognition book which shows ships of that class at various relative headings, and as TFA says it's especially hard to tell the difference between perpendicular and near-perpendicular relative headings.
Mind you, this also explains why dazzle was a promising idea in the first place. Calculating Angle On Bow was already the hard part of ship-against-ship targeting, why not try to make it even harder?
SH3 vets plotted relative positions to get heading much more reliably, which was something that was also insanely difficult for sub captains.
With some trig you can get relative headings by taking bearing measurements, waiting 30s, and then taking more, but speed must be known.
To get full heading and speed you can do the same thing multiple times but now we're in a least squares problem and it has plenty of singularities.
The most reliable method for me was to pass in front of the ship submerged the fire tail tubes or turn around if you have enough time.
Insanely difficult for fast moving targets.
I played so much SH games from the first days on, that I went and did my PhD on tracking using bearing measurements (albeit mostly applied and only a tiny theoretical contribution).
Well, at least in WW2 they had mechanical computers that could use the input width of the vessel and the class to estimate the range, heading, and firing angle to set the torpedoes up. There's a good series of youtube videos by a sim player that teaches how to use the TDC: https://www.youtube.com/watch?v=ANk6hZCcVRw - it's very in depth, and demonstrates how much effort it takes to get a firing solution, as you say.
Adding to the difficulty is the possibility of observers seeing the incoming torpedoes and a fast-moving,
maneuverable ship dodging them.
Fast and maneuverable as in .. the USS New Jersey, able to sidestep a spread of five torpedoes from a Japanese destroyer.
This article has good background, context, and explanations [1] They skipped CUDA and instead used PTX which is a lower level instruction set where they were able to implement more performant cross-chip comms to make up for the less-performant H800 chips.
> Moreover, if you actually did the math on the previous question, you would realize that DeepSeek actually had an excess of computing; that’s because DeepSeek actually programmed 20 of the 132 processing units on each H800 specifically to manage cross-chip communications. This is actually impossible to do in CUDA.
You can do this just fine in CUDA, no PTX required. Of course all the major shops are using inline PTX at the very least to access the Tensor cores effectively.
It's been a big pain for Tesla as well, where their tiny 8GB emmc on the center screen would fail since they logged to it too much... 134,000 vehicles recalled eventually after they denied it was an issue.
Jesus Christ are they amateurs? These are steel boxes on wheels and we're dealing with the same issues as shitty 200 dollars android tablets from 10 years ago.
That's because all who gets hired at these hyper-fast startups are fresh graduates who can do leetcode by heart.
The people who have been in the field for a decade or more can't be arsed putting up with all that and so you get stupid issues which were solved years ago but the devs were not aware of them.
That affects the infotainment computer only so driving is unaffected. You just wont be able to check your speed etc. But yeah, it's way too common of a mistake.
I don't know how their cars' UI is designed (and I hope I never have to) but if it's the only way to determine car speed or battery capacity, then this goes well beyond infotainment. No wonder they were forced to do a recall.
They have so many incredible artifacts (for weights and measures but also so much more: engineering, physics, civil engineering, machining,...)
[1]: https://collections.arts-et-metiers.net?id=13404-0001-