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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.









  • 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).



  • You mentioned ham radio — definitely fun! It’s a process to get into it though, as you need to study/pass an exam, and then you need a radio. Radios range from cheap ($25 or so) in the VHF/UHF (“walkie talkie”-style) to more expensive for an HF rig ($1000 range for 100W HF). If you want to get into low power (“QRP”) it can be much cheaper. You also need a fair amount of space for a good antenna setup…

    There are tons of different communication modes, some without a computer and, like you mentioned, some that use computers. wsjtx and fldigi are popular programs.

    Good luck!









  • qjkxbmwvz@startrek.websitetolinuxmemes@lemmy.worldLinux is too hard
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    3 months ago

    Windows is just as hard as linux, harder even with all the layers of obscurity.

    With Windows, there is 1 current version of Windows (11), 1 “almost current” (10), 1 “outdated but you’ll maybe see it” (8.x) and only a few “you’ll probably only see this in obscure situations” versions. Linux has as many “parent” distros/package management systems (apt, rpm, pacman, etc.). This definitely complicates things, as each distro family does things slightly differently.

    And we haven’t even touched the window manager/DE choices, of which there are a ton (as opposed to Windows). “Combinatorical explosion” maybe isn’t the right phrase, but you get the idea — Debian with i3wm is wildly different from Fedora Plasma.

    This is all a good thing though, as Linux users tend to like the choice and flexibility — but it does mean that the “right way” to do something on Linux is very dependent on your particular setup, which isn’t the case with Windows.

    (I have used Linux for the last 20+ years, and it’s definitely my preferred setup, and am lucky enough that I rarely use Windows for work, and never for personal use.)