• Rivalarrival@lemmy.today
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    5 days ago

    Show me.

    If I’m building a railroad, I’m going to need mm precision in laying sleepers and rail, sure. But I’m not particularly interested in km magnitude while I’m driving spikes.

    If I’m driving a train over that rail, I’m interested in km lengths, but I can tolerate several hundreds of meters of imprecision in those measurements. No need to convert to meters, let alone mm for that measurement.

    The closest I’ll come to needing both km magnitude and mm precision is in figuring out how much material to order.

    But, when I do that, what I will actually be converting isn’t length to length. I’ll be figuring out how many sleepers per km, how many rail segments per km, how many buckets of spikes per km. None of those will be simple metric unit conversions.

    • VoterFrog@lemmy.world
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      4 days ago

      But, when I do that, what I will actually be converting isn’t length to length. I’ll be figuring out how many sleepers per km, how many rail segments per km, how many buckets of spikes per km. None of those will be simple metric unit conversions.

      This is actually the primary strength of imperial and the impetus behind most of its conversion ratios. Base 10 is just terrible for being divided. But if you have a mile of railroad, you can place your rail and stakes regularly at almost any foot-length and come out even.

      • Rivalarrival@lemmy.today
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        4 days ago

        Exactly. Our base-ten number system is cursed. A base-twelve metric system would be gorgeous. Our existing clocks would already be metric.

        In addition to scaling by “10” (pronounced “ten”), current Metric Rulers commonly scale by 2 when going from centimeter to 1/2 centimeter markings, or by 5 when going from cm to 2mm markings, depending on the degree of precision required. Rarely do rulers actually scale from cm to 1mm. You typically need calipers to make measurements smaller than 2mm.

        With base-twelve, we’d still be able to scale by “10” (pronounced “twelve”), but we’d also be able to scale by 2, 3, 4, or 6.

        • antipiratgruppen@lemmy.dbzer0.com
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          4 hours ago

          Rarely do rulers actually scale from cm to 1mm. You typically need calipers to make measurements smaller than 2mm.

          I’m pretty sure most rulers and measuring tapes I’ve ever seen had 1 mm markings.

          We’re talking rulers of typically 10-30 cm marked length and made of plastic or metal, and longer measuring tapes made of either flimsy metal (in a casing with a lock-button) or those softer textile tapes.

          The only exception I can think of, that has only 1 cm markings, is a wooden 1 m teachers’ ruler made for blackboard use. But you do you with the calipers.

          • Rivalarrival@lemmy.today
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            2 hours ago

            Shows you how many metric rulers I’ve used… In my experience, most have four marks, at 2mm, 4mm, 6mm, and 8mm. Some have only had the 5mm mark. But searching for images, I can’t find any that look like the tapes I’m using, so my experience must not be the norm.