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Joined 2 years ago
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Cake day: February 1st, 2024

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  • Prescriptive vs. descriptive is different in colloquial language than in science.

    If my data logger captures 1kB/km, how many bytes/meter is that? In every other quantitative unit I can think of, the k should cancel out; but if you want computers to be special, that’s your preference.

    Metric sucks. Powers of ten are arbitrary, a fluke of biology. Powers of two are the only sensible way to make a system of measurements.

    Then why are you trying to shoehorn binary into decimal? As in: why are you using decimal prefixes in the first place? Answer is probably that most people have intuition behind powers of ten. You can easily express in log2-bytes instead (a GiB is 30, a TiB is 33…etc.). Be the change you want to see!

    I’m born and raised in the USA, and while imperial units can be handy for a few every day tasks, there’s a reason why the sciences in the US tend to use metric.

    Regarding cooking, I’ll stick to metric, measured by weight. I can double, halve, or multiply my recipe by pi, and all I have to do is look for a different number on my scale.


  • Giga, Mega, Kilo…these are all SI prefixes; they differ by a factor of one thousand, which is very clean in base ten.

    Ten in binary systems isn’t special, but two is; and two to the ten is very nearly a thousand, and a thousand separates the major SI prefixes. This is a neat coincidence, but should not IMHO change the meaning of the prefix.

    Metric units are awesome in large part because of the use of prefixes; messing up the meaning of prefixes is a disservice to the SI/metric system. Giga == billion independent of the context. A light-year is close to 10 petameters, but no one would claim it’s exactly 10Pm.

    Now, if you want to call it an “imperial gigabyte,” by all means…




  • I do something similar — I have a raspberry pi and a HD, with daily rsync and snapshots (monthly retained indefinitely, weekly retained for a month, daily retained for a week). It’s at family’s house, connected to my home via WireGuard via a VPS. Tailscale (or anything really) would also work here.

    It’s a great setup! Just have some watchdog reboot if it can’t talk to home (a simple cronjob with ping -c1 home.lan || reboot or similar).

    Even our “slow” 35Mbps upload speed is way more than enough for incremental rsyncs of my Immich library. The initial sync was done in person, though.







  • Aluminum foil is very common in physics labs. And a main use for it is “baking”! To get ultra high vacuum (UHV)* you generally need to “bake out” your chamber while you pump down. Foil is used same as with baking food — keep the heat in and evenly distributed on the chamber.

    Sadly, it’s usually not food grade aluminum foil, as that can contain oils, and oils and vacuum are generally a big no-no.

    *Just how good is UHV? Roughly: I live in San Francisco, which is ~7 miles by ~7 miles (~11km). Imagine you raise that by another 7 miles to make a cube. Now, evacuate every last molecule of gas out of it. Now take a family sedan’s trunk, fill it with 1 atmosphere of gas, and release that into the 7 mile cube. That’s roughly UHV pressure.



  • ZigBee router thing:

    I’ve been happy with the SMLIGHT SLZB-06M. You can easily flash firmware, and it has PoE which was important for me. I believe it also supports Thread, but I haven’t tried this yet (and I’m not sure if it supports it at the same time as Zigbee).

    Zigbee smart plugs from Third Reality have been pretty solid in my experience, and they report power usage.

    For circuit breaker level monitoring, I have an Emporia Vue2. I have it running esphome, completely local — unfortunately this requires some simple soldering and flashing, so it’s not turnkey. But it’s been rock solid ever since flashing it. (Process is well documented online.)

    I’ve had decent luck with cheap wifi Matter bulbs, but provisioning them is finicky, and sometimes they just crap out and need to be power cycled; Zigbee bulbs (e.g., Ikea) have generally been reliable, though sometimes I’ve had difficulty pairing them initially. After power cycling a Matter WiFi bulb, it takes a while for it to respond to Home Assistant; Zigbee bulbs generally respond as soon as you power them on.

    I have a wired smart light switch from TP-Link/Kasa (KS205), and it’s been completely hassle free (and totally local — Matter over wifi). The Kasa smart switch dongles I have work flawlessly but need proprietary pairing, and I’m afraid to update firmware in case they lose local support.

    Good luck! Fun adventure :)