Dear Lord you are thick. And how, pray tell, is the grain defined? Well, currently it's defined as 64.8 (more or less) grams. Historically, though, it was defined as the weight of a wheat seed... hence "grain." You think that's more accurate than defining a weight based on a platinum-iridium cylinder kept in climate-controlled storage?
...useless definition as no one here can possibly use an instrument that accurate.
And yet it's a big deal when a kilogram standard fluctuates by 0.0000000019%.
The kilo is a useless measurement and was nothing more than an abitrary measurement.
"Arbitrary?" It was initially defined as the mass of one liter (1000 cubic centimeters) of pure water at a fixed temperature, which is a hell of a lot less arbitrary than the weight of a frickin' seed.
No, you are thick. All kinds of people have come up with all kinds of units of measure for good reason and along come the French to change it to some arbitrary units of measure. Just look at your silly conversion factors, 0.453592338 kg of that 64.8 of the other. They changed the meter from one measurement to another once the other didn’t work out. The kilogram is a volumetric mass versus a weight against standard gravity, etc, etc, etc.
SI is what you get when politics and committees get involved.
“”Arbitrary?” It was initially defined as the mass of one liter (1000 cubic centimeters) of pure water at a fixed temperature, which is a hell of a lot less arbitrary than the weight of a frickin’ seed.”
Initially an arbitrary measurement, what is it today?? What does a mass of one liter equal? Anything in the real world?? Anything? Again, arbitrary. Was then and still is. So is the meter. As I have said before, they changed it from a measurement against the Earth to the speed of light. Yeah, that’s stable and neither measurement is any whole number of value.
1 grain = 64.79891 milligrams