• Railcar8095@lemmy.world
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      5 months ago

      It’s measuring speed, speed of light is 1 dumbass.

      Which proves God is American (anything except metric)

      • Teppa@lemmy.world
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        5 months ago

        I learned recently that it was the Babylonians who invented the hour and the minute as a unit of time, and they used base 60, which I thought was pretty neat. Then we created seconds and milliseconds in base 10.

        • ChonkyOwlbear@lemmy.world
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          5 months ago

          IIRC, they picked 60 because it could be evenly divided into 1/2, 1/3, 1/4, 1/5, and 1/6 which allowed them to stick to whole numbers more easily.

          • ILikeBoobies@lemmy.ca
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            5 months ago

            If you use your thumb to count the sections of 4 fingers you get 12.

            Then you hold up a finger on your other hand. When all 5 are up you have 60.

            • RustySharp@programming.dev
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              5 months ago

              I have never accepted this explanation. Yes, using base 12 is logical and well documented. But that means you’ve got 12 on the other hand as well. 144 would’ve made more sense.

              • Feathercrown@lemmy.world
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                5 months ago

                Yeah, what that user is describing is a mixed base system, which is pretty uncommon-- but then again, not for the people who invented time, since we have either 24|60|60 or 2|12|60|60 divisions for that. 5|12 would not be that weird.

        • Railcar8095@lemmy.world
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          5 months ago

          Any idea how they tracked time? AFAIK solar clocks are not consistent during the year. I can imagine some sort of water clock, but they would need a master one to use as reference or very accurate specifications to reproduce.

          • UnspecificGravity@piefed.social
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            5 months ago

            Solar clocks are consistent during the year because noon is always at local noon. They just stop telling time effectively early or later depending on the season (i.e. how long the sun is shining). You just measure time around noon and you are always accurate to local time (even the modern era navy did this). It only matters if you need to synchronize time from very far away, which ancient people didn’t really need to do do.

            • Railcar8095@lemmy.world
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              5 months ago

              I mean in the sense of measuring hours. Is it a constant angle from noon to 13:00, for example?

              Even the “local noon” would drift of you want you measure with constant hours of a24th of a day.

              • UnspecificGravity@piefed.social
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                5 months ago

                Is it a constant angle from noon to 13:00, for example?

                Within a margin of a few minutes (i think 15 minutes at the most).

                Even the “local noon” would drift of you want you measure with constant hours of a24th of a day.

                We are talking about a matter 20 to 30 seconds here.

  • Zwiebel@feddit.org
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    5 months ago

    Because we tried to make the meter one 40-millionth of the earths circumference, failed, and ended up at a 299792458th of the distance light travels in a 60th of a 60th of a 24th of the time earth doesn’t take to make a full rotation.

    This one’s on us

    • merc@sh.itjust.works
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      5 months ago

      Having said that, we’re pretty lucky that using those pretty arbitrary values we ended up with a speed that you can approximate as 300 million m/s and be off by less than 0.1%.

      • JackbyDev@programming.dev
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        5 months ago

        My understanding is that the person proposing the meter’s distance immediately caught their mistake but didn’t bring it up because they didn’t want people to think the system was flawed, not so much that the measurement was off.

    • _stranger_@lemmy.world
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      5 months ago

      At least one second has a simple origin, and totally wasn’t back-defined in 1967

      oh wait

      The current and formal definition in the International System of Units (SI) is more precise:

      The second […] is defined by taking the fixed numerical value of the caesium (Cs) frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the Cs-133 atom, to be 9192631770 when expressed in the unit hertz, which is equal to s−1.[1]

  • teft@piefed.social
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    5 months ago

    The speed of light is a tautology. We define it via how many meters light travels in a second. And we define the meter by the same measure. It’s just the distance light travels in 1⁄299792458 Of a second.

    • wolframhydroxide@sh.itjust.works
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      5 months ago

      c is a measurable constant, not some unit that is arbitrarily defined. Like Boltzmann’s Constant, or the ground state hyperfine transition frequency of the Cesium-133 atom… it just… Is.

      Therefore, it is a useful tool to define units. You claim it is a tautology because we write it in units of meters per second, while the meter is defined based on c. This is easily disproven, as you can represent the speed of light in any unit of velocity. It is a fundamental constant, derivable through experiment without any units a priori.

      • teft@piefed.social
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        5 months ago

        It’s not about the units i used. It’s about using something to define itself. The same problem happens when you use c to define empty space since empty space can define c.

        Once you decide which units are used in maxwells equations then the electromagnetic permeability and permissivity pops out as a proportions of c.

        Read more Feynman if you don’t believe me.

        • wolframhydroxide@sh.itjust.works
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          5 months ago

          That may be, and I’ve been meaning to dig into my copy of the Lectures, but that’s moving the goalposts. You said that it was a tautology because it was defined by the meter, and the meter was defined on it. That statement is demonstrably false.

          • teft@piefed.social
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            5 months ago

            I used the meter because that’s generally what is used for measurement in scientific endeavors. There was no goal post moving if the statement applies for all SI measurements.

            • Morlark@feddit.uk
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              5 months ago

              Literally the entire point of the comment that you’re responding to is that it isn’t true for the metre, and it isn’t true for any SI units.

              Your entire claim of tautology rests on the assertion that the speed of light is defined by something external to light itself. That’s false. It remains false irrespective of which SI measurements you swap in.

              Just because the speed of light can be expressed in terms of SI units, doesn’t mean its definition depends on them. Which is the point that wolframhydroxide was making.

              This directly disproves your original assertion of tautology.

        • bitwolf@sh.itjust.works
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          5 months ago

          But isn’t the measurement of the speed of light our own proportion derived from the constant that is 1g of water at 1ATM?

    • Undearius@lemmy.ca
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      5 months ago

      This got me thinking if we defined the metre to be a more round number, like 1⁄300000000.

      It would shrink the metre by 0.6918mm.

      Now I’m curious about what implications that would have.

    • hansolo@lemmy.today
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      5 months ago

      The small thing defines the big thing that defines the small thing that defines…

  • Lumidaub@feddit.org
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    5 months ago

    A mile is 0.000000000000**1701** light years. How d’you like them Kaferian apples?

  • ceenote@lemmy.world
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    5 months ago

    I’m a dumbass? I’m not the one deciding all speed should be scaled to a fraction of the fastest thing that exists, dipshit.