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Joined 1 year ago
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Cake day: February 1st, 2024

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  • That’s…not really a cogent argument.

    Satellites connect to ground using radio/microwave (or even laser), all of which are electromagnetic radiation and travel at the speed of light (in vacuum).

    Light in a fiber travels much more slowly than in vacuum — light in fiber travels at around 67% the speed of light in vacuum (depends on the fiber). In contrast, signals through cat7 twisted pair (Ethernet) can be north of 75%, and coaxial cable can be north of 80% (even higher for air dielectric). Note that these are all carrying electromagnetic waves, they’re just a) not in free space and b) generally not optical frequency, so we don’t call them light, but they are still governed by the same equations and limitations.

    If you want to get signals from point A to point B fastest (lowest latency), you don’t use fiber, you probably use microwaves: https://arstechnica.com/information-technology/2016/11/private-microwave-networks-financial-hft/

    Finally, the reason fiber is so good is complicated, but has to do with the fact that “physics bandwidth” tends to care about fractional bandwidth (“delta frequency divided by frequency”), whereas “information bandwidth” cares about absolute bandwidth (“delta frequency”), all else being equal (looking at you, SNR). Fiber uses optical frequencies, which can be hundreds of THz — so a tiny fractional bandwidth is a huge absolute bandwidth.















  • Same — rsync to a pi 3 with a (single) ZFS drive at family’s house. Retain some daily/weekly/monthly snapshots.

    I have a (free) VPS with static IPv4 which is how I connect everything.

    Both the VPS and the remote site have limited network speed (I think 50Mbps for VPS), so the initial sync was done sneakernet (well…“airplane net”). Nightly rsync is no problem bandwidth-wise, and is mostly just any new videos I’ve uploaded to my local Immich instance.



  • I feel old…when I was learning how to run Linux I started with an old 386 (maybe 486?) my dad wasn’t using. I think it had 32MB RAM, which was fancy for those machines.

    We had dial up at the time, so only one machine could be on the Internet. So, I set up a modem on the x86, plugged into an Ethernet hub (switch?), and learned enough ipchains (this was before iptables) to share a connection. It also ran Samba, an AFP server, and probably FTP and HTTP (just for local access) — but it worked for filesharing.

    It could also run MP3 streaming software which amused me because the machine itself was too slow to decode MP3 (but that’s not necessary to stream).


  • I just wish we’d have neither inflation nor deflation.

    Some tech has followed this pattern. For example: entry level Mac laptop in ~2000 was the iBook, priced at $1599 ($3k+ in today’s dollars). The current entry level Mac laptop (M4 Air) starts at $999 — cheaper in absolute dollars, and way cheaper in relative dollars.

    (Macs are just an example since Apple doesn’t have a very extensive product list, so there’s only one “entry level” laptop to choose from. And yes it’s fair to ask if the relative specs have just gotten worse, but I think this is also the opposite — the iBook was iirc criticized as being underpowered, whereas the M4 Air is afaik well regarded.)