• FiskFisk33
    link
    fedilink
    English
    arrow-up
    78
    ·
    1 month ago

    fun fact, that would make the transmission slower.

    According to wikipedia cat5 cable has a propagation delay of 5.30 ns/m, which works out to about 62% of the speed of light. While radio waves propagate at the speed of light.

    • LadyAutumn@lemmy.blahaj.zone
      link
      fedilink
      English
      arrow-up
      24
      ·
      edit-2
      1 month ago

      Yeah, the reason ethernet is generally faster compared with wifi is mainly due to interference from physical objects between the device and the transmitter. Not as much an issue when you’re issuing commands into the vacuum of space from large, high-powered antennas.

    • zaphod@sopuli.xyz
      link
      fedilink
      English
      arrow-up
      6
      ·
      edit-2
      1 month ago

      Radio waves always propagate at the speed of light, it’s just that the effective speed of light in copper and glass fibre is lower than that in air/vacuum.

      This means that if you have long cables at some distance you’ll get a lower delay by using low earth orbit satellites like Starlink. Assuming a total distance via satellite of 1000km and the effective speed of light in glass fibre to be 2/3 c, cables over 667km will have a higher delay than the satellite.

      • psud@aussie.zone
        link
        fedilink
        English
        arrow-up
        1
        ·
        29 days ago

        Speed of light in fiberoptic cable is slower than c for a different reason. The light is in something close to vacuum, signals travel slower than c because the light doesn’t follow a straight path, it zig zags bouncing off the walls.

        A radio wave or laser in reasonable vacuum (in orbit for example) will be lower latency than a signal on a fiber link the same length

        I’m expecting lower ping via starlink than fiber once starlink has laser links between satellites

      • mindbleach@sh.itjust.works
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 month ago

        Some fiber-optic cables are faster than others, because they’re full of air. Hollow-core fibers have a large central cutout and/or a close hexagonal packing of smaller glass tubes. The latter are technically a “photonic crystal.”