• Icalasari
    link
    fedilink
    349 months ago

    Trying to picture how you do this with those. Brain is stuck on hanging rock from wood with string which feels like I’m going the wrong way

    • Deconceptualist
      link
      fedilink
      English
      26
      edit-2
      9 months ago

      Drafting* class taught me that you can build any structure with just a T-square, a compass, a pencil, and some basic math.

      *As in the precursor to Computer-Aided Drafting. My school was cheap and didn’t let us use AutoCAD till the 2nd semester.

      But anyway, place the straight piece of wood across a gap. One end of the string goes around the middle of the wood, the other end hangs down where you tie the rock. You can visually tell with decent enough accuracy if the rock is hanging closer to one side (not level) or just straight down (level). If you can’t tell, get a longer string.

      • Tar_Alcaran
        link
        fedilink
        229 months ago

        some basic math.

        The pyramids at gizeh predate most of that. They predate algebra by some 800 years.

        Of course, despite Pythagoras not being born for some 2000 years, they DID have Rope stretchers to create square angles. They also had square levels and plumb bobs for making straight blocks and level surfaces.

        You don’t even need maths, just rope and gravity.

        • shuzuko
          link
          fedilink
          English
          69 months ago

          https://en.m.wikipedia.org/wiki/History_of_mathematics

          “From 3000 BC the Mesopotamian states of Sumer, Akkad and Assyria, followed closely by Ancient Egypt and the Levantine state of Ebla began using arithmetic, algebra and geometry for purposes of taxation, commerce, trade and also in the patterns in nature, the field of astronomy and to record time and formulate calendars.”

          The first “true” pyramids were not built until ~2613. Prior to that it was all step pyramids, which are much less complex - just put a bunch of consecutively smaller squares in a stack. Even then, Djoser was started in ~2670, several hundred years after the “introduction” of basic math. Just because we don’t have extant physical mathematical texts surviving from that time doesn’t mean they didn’t know how to do math.

      • prole
        link
        fedilink
        English
        4
        edit-2
        9 months ago

        Yeah dude, I took a drafting class way back in HS (really enjoyed it), yet have maybe seen three drafting tables since (and I’m in a field that would have previously had countless).

        I know that stuff was basically immediately made obsolete by CAD and what not, but there was always something relaxing and meditative about sitting down at (or standing if you so choose) a drafting table, armed with nothing but a pencil, an eraser, a T-square, a protractor, and a couple plastic triangles, and coming up with some really impressive looking shit with perfect perspective.

        If I had the room for one, I’d def get a drafting table… lol I’d probably end up using it to hang wet clothes on to dry.

      • JJROKCZ
        link
        fedilink
        39 months ago

        Think your school was cheap? My school only had CAD on 3 machines and you had to take 4 YEARS of drafting courses to be allowed to use it, I graduated in 2012… this shit wasn’t new tech at that time lol

    • @[email protected]
      link
      fedilink
      169 months ago

      That’s actually all there is to it.

      Out the stick where you want the thing to be level, and hang a rock off it with string.

      The rock hangs straight down. Adjust what the stick is sitting on until the stick is perpendicular to the string.

      It’s not the most accurate or easiest to use tool we have available today, but they’re still used for vertical alignment.

      It’s one of the oldest tools we have. Hasn’t really changed since they were used during the building of the pyramids.

    • @[email protected]
      link
      fedilink
      149 months ago

      The rock and string, with help from gravity point down to the ground. If angle between the stick and string isn’t 90°, then it’s not level.