That's literally just an XLR3 plug. It's used for analog audio and DMX lighting controls.

Don't know why you'd put it in a rock though.

Unfourtunately, I couldn't find a source stating it would be required. AFAIK it's been assumed that they would use perceptual hashes, since that's what various companies have been suggesting/presenting. Like Apple's NeuralHash, which was reverse engineered. It's also the only somewhat practical solution, since exact matches would be easily be circumvented by changing one pixel or mirroring the image.

Patrick Breyer's page on Chat Control has a lot of general information about the EU's proposal.

Matched using perceptual hash algorithms that have an accuracy between 20% and 40%.

There's a smaller version of type F that has the same frame as type N, just missing the middle pin, so it is reversible. It has the same risk of reversing neutral and phase as type F, but (while I'm no expert) that has never been a problem for me.

It's missing the European high voltage plugs as well.

relevant xkcd

It is open source, licensed under the Apache License 2.0.

EDIT: Found it on f-droid: https://f-droid.org/en/packages/app.organicmaps/

Have you tried Organic Maps? Works pretty well for me.

base12 has the advantage of being divisible by 2, 3, 4 and 6, while base10 is only divisible by 2 and 5.

Optical Character Recognition. Basically just extracting text from an image.

You can do this in VLC, though it's not very practical. VLC's equalizer has a preamp slider, it's just not great if you want to change it all the time.

Here's a circular rainbow from an aircraft a skydiver:

EDIT: image embedding didn't work

EDIT 2: not from a plane

EDIT 3: sorry for all the edits, fixed image

I'm not an expert, but I guess it would depend on the speed of sound in the rod.

Fun fact about that: in morse code, SOS is a prosign. This means it gets its own special rules.

Rather than being three seperate letters (... --- ...), it's one letter without any letter spaces (...---...). This is something that applies to all prosigns in morse code, though most of them are just two letters long.

Also, when sending it on repeat you just continue the pattern without any spaces. Instead of ...---... ...---... (with a letter space) or ...---.../...---... (with a word space), you send ...---...---...---...---... and just keep continuing the pattern. iirc SOS is the only prosign where this is a thing.

Other prosigns are for example HH (........) to indicate a correction to something previously sent, and SK (...-.-) (silent key) to signal that you have finished with the current conversation and the frequency is now clear.

No problem, thanks for replying.

That makes sense. It looks like a really clever way of letting the boot process allow for basically any arangement. Thanks!

They do, but compounding errors are always a problem with inertial navigation.

Instead of GPS, they can use fixed radio beacons like VOR and TACAN (which I think are both just US systems, but there are similar systems around the world and at major airports). This is basically the system that was in use before GPS.

EDIT: grammar

AM Radio has an extremely important role in emergency broadcasting, because you can cover a whole continent using just 3-4 broadcasting stations, and it is so easy to demodulate, that you can build completely analog recievers that need no power source (they use the carrier wave as a power source). This also means that AM receivers are very cheap, so in a lot of developing countries the only broadcasts most people can afford, and will reach them are AM.

I think we should keep AM radio around, at least for emergencies.

Also, unfortunately, when HF bandwidth gets freed up, it mostly ends up going to companies that use it for high frequency trading, and not to things where it would benefit the public, like ham radio, or digital broadcasts.

Thanks for explaining it! So systemd-boot finds the kernel in the EFI partition, which it then loads, and then that kernel loads another kernel from the main partition, which is then the full OS.

Is there a reason it's done this way, and not just the bootloader loads the main kernel?

Also, are the two kernels the same, or does this use two different kernels?

If you use btrfs snapshots and systemd-boot instead of grub, then be carefull restoring updates from before a kernel update.

If I understand it correctly, with systemd-boot the kernel lives in the EFI partition, while the kernel modules live in the main (btrfs) partition. If you restore a snapshot with a different kernel version, it doesn't restore the kernel itself, but the kernel modules have different filenames, which stops the system from being able to boot.

At least that is my understanding of the problem, from having to debug it twice (just start a live-boot system and use Timeshift to restore the system to after the update again). The next time I install Linux, I think I'll go with grub instead of systemd-boot.

That being said, I really like btrfs snapshots as a sort of "almost backup" (still do regular backups on an external drive). They are quick and easy, and most packet managers can be setup to automatically make a snapshot before installing/updating stuff.