(no subject)

the concept of clocks fucks me up sometimes

so ok suppose you want to know what time it is and you have some physical phenomenon that takes a predictable amount of time so you say "ok right now it is [time] and every X repetitions of this phenomenon is Y units of time, so we just count how many times it happens from now and we know what time it is"

which is great except like. all measurements have some error. we don't know with infinite precision how the amount of time the phenomenon takes compares to other indicators of time, like the sun. and for most things, that fact that measurement error exists doesn't matter, right. I don't need to know what time it is to the millisecond. I mostly don't even really need to know it to the second. (minute though, yeah, i need to know what minute it is).

but. but! time is cyclical. or at least our external referents for it, like the rotation of the earth on its axis, are cyclical. if i have a thing that measures seconds with an error of 0.1%, it'll be off by a second after every thousand, which is like twenty minutes (~17). and it'll be off by a minute after 60 times that, which is like two thirds of a day (around 17 hours). And it'll be off by an hour after 60 times that, which is ~40 days. no clock i ever owned was off by an hour after a month, so they must've had better precision than that. you need better than millisecond precision to have a clock that's worth anything

back in the 18th century getting accurate clocks on ships was a big problem, because you can use a precise clock to find your longitude when far from shore (basically if you have a clock set to GMT and you can see what the sun is doing in the sky, you can find your timezone, so to speak, which is also how far east or west you are. it's more complicated than that but this is already a parenthetical inside a digression). but the most precise clocks they had were pendulum clocks that didn't work great on ships. anyway some guy made a lot of money building a clock that was precise enough even on a ship that it'd work for that purpose and if wikipedia is to be believed it'd lose less than five seconds after ten weeks, which is a precision better than one part in a million. with fucking 18th century technology! and i don't know how precise the clocks that weren't built to go on ships were, apparently better. what the fuck.

and it's been like 300 years since that and now we have atomic clocks and whatever but like. i still get angry at my microwave clock because it tends to drift forward a few minutes over months. my microwave! a device built entirely for warming food, that does not need to measure times more precisely than to the second (i can't set cooking times in milliseconds, i've tried), but it can still keep track of minutes after weeks. that 's not good enough to use as a marine chronomoter but it's a microwave.

but time is cyclical, and tiny imprecisions accumulate day after day, and sometimes i glance at my microwave when i walk by it making my morning coffee and it tells me i should be sitting down at my computer and logging in to a video meeting but actually it's fine, the microwave runs fast, i have five minutes to make coffee.

clocks are fucked up and my microwave should not be trying to be one. it's ok to just be a microwave. my phone tells me what time it is instead, and it's connected to the internet to do that because if it's off by a few seconds OTP authentication doesn't work.