• jumperalex@lemmy.world
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    1 day ago

    Not arbitrary.

    Since 2019, the meter has been defined as the length of the path traveled by light in vacuum during a time interval of ⁠1/299792458⁠ of a second, where the second is defined by a hyper-fine transition frequency of caesium.

    https://en.wikipedia.org/wiki/Metre

    • verdare@piefed.blahaj.zone
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      1 day ago

      I mean, that is pretty arbitrary. The reason the divisor is that specific constant is because we already had meters before we knew the speed of light.

      • saltesc@lemmy.world
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        1 day ago

        we already had meters before we knew the speed of light.

        It’s true.

        Genesis 1:1 In the beginning God created the heavens and the earth and the metric system.

        Genesis 1:3 And God said, “Let there be light,” and there was light.

        • TeamAssimilation@infosec.pub
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          1 day ago

          One light year is 9.4607379e+15 meters, so there’s a power of 10 that could give us a unit of length close to 94 cm. That would not be as arbitrary.

          But fuck me if we discover the speed of light in a vacuum has not been constant along the history of the universe, the c would be an awful base for cosmic distance, or very long term science.

          But don’t worry, humanity doesn’t look like it will exist long enough to do very long term science.

          • MotoAsh@piefed.social
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            19 hours ago

            Yes and no. Humanity is doing a great job at fucking itself in to extinction (along with most other megafauna species on this planet), but astrophysicists/astronomers already have to deal with the entire history of the universe to explain things.

    • marcos@lemmy.world
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      1 day ago

      You are correctly trying to say it’s well defined, but you are complaining about the wrong comment. You should check the meaning of “arbitrary” again.

      Anyway, it’s not entirely arbitrary because it was created to represent a “round” fraction of the Earth’s circumference that is similar to the length of a person’s arms. But it deviated from that too, so it’s subjective how much that counts.

        • KubeRoot@discuss.tchncs.de
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          24 hours ago

          Because people weren’t traveling around the moon, mars, or the sun back then, they were traveling around the earth :V

            • KubeRoot@discuss.tchncs.de
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              5 hours ago

              Yeah, in history we’ve really been ignoring the experiences of the sunwalkers, but thankfully society is leaving those prejudices in the past now.

              It’s all arbitrary one way or another, but the meter was (seemingly) chosen for a specific purpose, creating a unit based on a good and verifiable frame of reference (though probably not as absolute as people thought back then), while also having 1 meter be a convenient and useful measure on a human scale.