Actual poster from 1917 that made me laugh. A lot.

Also, those motherfuckers are measuring the weight of those balls in kilograms, aren’t they?

  • backgroundcow@lemmy.world
    52·
    3 months ago

    … weighs one gram … An amount of hydrogen weighing the same amount has exactly one mole of atoms in it.

    Not only was this never true - the sentence would have to have say “An amount of carbon-12 atoms weighing 12 times this amount has exactly 1 mole atoms in it” (far less elegant) – but not even this is true any longer after the fuckup in redefining the mole in 2019, after which all these relations between amount of substance and mass are only approximate.

    • repungnant_canary@lemmy.world
      23·
      3 months ago

      the fuckup in redefining the mole in 2019

      What? It was necessary due to our observations of the universe (on every scale), not some arbitrary “fuckup”

      • backgroundcow@lemmy.world
        3·
        3 months ago

        Nope, this redefinition isn’t necessary, it is a choice SI made. Nothing would have broken by keeping an exact relationship between amount of substance and mass, it would just have retained the interpretation of Avogadro’s constant from before 2019 (experimentally determined vs a defined constant).