• thebestaquaman@lemmy.world
    link
    fedilink
    arrow-up
    0
    ·
    edit-2
    5 days ago

    Oh, let’s also remember that A4 is a member of beautiful variant of an “SI system for paper”. Want a paper the size of an A4 folded double? We have A85. Want something that folds perfectly to A4? A3. One more fold? A2.

    • Statement: “I want a piece of paper that I can fold twice to get exactly a US letter size.”
    • Response: “You must be crazy.”

    Edit: Did a fat-fingering

      • elucubra@sopuli.xyz
        link
        fedilink
        arrow-up
        0
        ·
        5 days ago

        2A0, and next 4A0, but there are rarely used. From A0 you mostly print from rolls, so you define the width. Large offset printing presses use formats that allow multiple A sized pages, either single or double for binding, and the needed trims.j

    • f314@lemmy.world
      link
      fedilink
      arrow-up
      0
      ·
      5 days ago

      What on earth are you on about with those numbers? 😅

      A0 is the base size, with an area of one square meter. Fold that in half and you get A1. Fold that in half and you get A2, and so on. Regular printer paper is A4. You’ll rarely, if ever, see sizes smaller than A6.

      • Rhaedas@fedia.io
        link
        fedilink
        arrow-up
        0
        ·
        5 days ago

        I was hoping that there was a metric baseline for this paper size, but it still bugs me that the dimensions aren’t “even”. 297mm? That’s no better than 8 1/2 inches.

        • halcyoncmdr@piefed.social
          link
          fedilink
          English
          arrow-up
          0
          ·
          5 days ago

          There is, but A4 isn’t the baseline, A0 is.

          A0 is 1m² with a ratio of 1:√2. Cut that in half along the larger side and you have A1, half it again and you have A2, etc. on down the line.

          The entire series maintains the same exact ratio down to A13 at 9mmx13mm.

          • surewhynotlem@lemmy.world
            link
            fedilink
            arrow-up
            0
            ·
            5 days ago

            So ridiculously dedicated to metric that they didn’t think to make A0 an exponent of 2, and then designed an entire system around dividing it by 2.

            A0 should’ve been 1.024 meters.

            • f314@lemmy.world
              link
              fedilink
              arrow-up
              0
              ·
              5 days ago

              You’d still get «weird» lengths in the other dimension, though. Remember, the aspect ratio has to be 1 to the root of 2 for the folding in half to work.

              Also, I don’t think 1024 would have been such an obvious number back in the late 1700’s, when this system was first thought up 😅

              There is a system of sizes where the shortest side of the base size is exactly 1 meter, though: the B system. The aspect ratio is the same as for the A sizes.

          • brachypelmide@lemmy.zip
            link
            fedilink
            arrow-up
            0
            ·
            5 days ago

            with A4’s divide-by-two shtick an A85 might unironically have a surface area of only like a couple atoms. it’s too late in the night for me to calculate this so i pass this task onto someone else

            • Pelicanen@fedia.io
              link
              fedilink
              arrow-up
              0
              ·
              5 days ago

              So, A0 has an area of 1 m2 and it’s halved for each next one in the series, giving A85 a surface area of 1/(285) m2 = 2.585×10-26 m2 = 0.02585 pm2.

              The smallest atom is the hydrogen atom with a Van der Waals radius of 120 pm which gives it a surface area of 4×π×1202 pm2 = 180956 pm2 or just over 7 million times larger than the A85.