• Eheran@lemmy.world
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    1 year ago

    Units closer related to everyday stuff are those that stick around. Like horse power or km. People don’t use Mm but instead 1’000s of km, even into the million km for cars. Even in space they still tend to use km like for the distance to the moon or sun. Only once the distances get absurdly large is there a shift to either another unit (light years) or the use of different notation (like 3.14E12 m).

    • aulin@lemmy.world
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      1 year ago

      As a Swede, using units that give numbers above ~100 starts to get unwieldy. Hence why we use mil (1 Scandinavian mile = 10 km) once we get to triple digits in km. “It’s 60 mil to Stockholm” is immensely more natural than “it’s 600 km to Stockholm”.

      • tunetardis@lemmy.ca
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        1 year ago

        That is fascinating! I had heard of the “metric mile” as being 1500m: the closest you can get to running a statute mile at international competitions.

        But I like this 10km mile idea! We could use something like that here in Canada. Sometimes we say “klick” here to mean km, so I have tossed around terms like “decaklick” and “hectoklick” but people look at me funny.

        • aulin@lemmy.world
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          1 year ago

          We’ve had different mil definitions in Scandinavia before, but at some point Sweden and Norway agreed to unite at 10 km, which is a really useful unit. Denmark just didn’t do it. They’ll give distances in hundreds of kilometers.

          I love this! Let’s use all the prefixes!

          It’s always been a pet peeve of mine that Sweden is seemingly the only country that uses dl (deciliter) and hg (hectogram, but we just say hekto, just like with kilo), which are to me vastly more useful units as they’re close to what you’re measuring. 2 hg salami or candy or whatever instead of 200 g, and 3 dl water instead of 30 cl or, god forbid, 300 ml.

          I see cooking shows from countries that normally use imperial, using metric by measuring everything in milliliters. It makes no sense! No recipe needs that resolution.

    • too_high_for_this@sh.itjust.works
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      1 year ago

      The astronomical unit AU is commonly used for things in the solar system. 1 AU is roughly the average distance to the sun, about 150 000 000 km

    • Melatonin@lemmy.dbzer0.com
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      1 year ago

      I know the metre has been defined by earth’s size, or other various things, all rather arbitrary. Wouldn’t it make sense to define it by the speed of light and a light year, divided into even portions? Start by dividing a light year (in a vacuum) by ten, and keep dividing by ten until we get a unit that is close to the useful size we are accustomed to?

      That way we could scale up, and I suppose that’s going to be useful in the future.

      • Kethal@lemmy.world
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        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
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          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.