• Kethal@lemmy.world
    link
    fedilink
    arrow-up
    12
    arrow-down
    1
    ·
    1 year ago

    It’s already defined that way - from Wikipedia "From 1983 until 2019, the metre was formally defined as the length of the path travelled by light in a vacuum in 1/299792458 of a second. After the 2019 redefinition of the SI base units, this definition was rephrased to include the definition of a second in terms of the caesium frequency ΔνCs. "

    • Melatonin@lemmy.dbzer0.com
      link
      fedilink
      arrow-up
      3
      arrow-down
      1
      ·
      edit-2
      1 year ago

      Just because it’s defined as some section of a light year does not mean it’s using a light year as a reference. You could use a foot and find the fraction of a light year that represents it, but that doesn’t mean that the foot is based on a light year.

      I’m saying the short measure that we use on a daily basis might be a BASE 10 portion of a light year. Not 1/299792458 of a light second.

      P.S. It’s like being on Reddit, being download for conjecturing.

      • Kethal@lemmy.world
        link
        fedilink
        arrow-up
        3
        ·
        1 year ago

        I see what you mean. That is just as arbitrary as using the Earth’s size or any other reference. There’s nothing special about a year.

          • accidental@lemmy.sdf.org
            link
            fedilink
            arrow-up
            1
            ·
            1 year ago

            it’s a hard thing for me to wrap my head around, but it’s cool when you think about it: there’s actually no possible shared reference; even with atomic clocks, based solely on the bouncing of cesium atoms ticking away, the distance travelled is dependent on acceleration in your reference frame.

            relativity really is!