TIL YIG filters (Yttrium Iron Garnet), which is used in microwave RF filters to make a pass-band that sits north of 3GHz.

This does _nothing_ to dispel the notion that RF engineering is just modern alchemical bullshit. Look at this simplified representation of a YIG filter on wikipedia. Oh yeah, you pass two microstrips at an angle near a mysterious Sphere Of Filtering, and its ravenous maw consumes the 0-3GHz frequencies to feed its demonic ambitions. But sure yeah, enjoy your filtered signal.

How to tell your OSS is ridiculously popular: people aren't 100% sure they _didn't_ embed it, and tack on the software equivalent of "packaged in a facility where peanuts were also present" to the license list.

This watch contains software, so statistically probably contains at least traces of curl.

I have just discovered that a popular brand of washer/dryer has a diagnostic function that is literally you hold your phone up to the washer and the machine screams AFSK tones down the phone to the support person, and I'm sorely tempted to buy one just to support the chaotic design choice of shipping an acoustic coupler in consumer hardware in 2023.