I believe that was because at the time of its discovery, that was the most accurately we could measure it. It’s still based on a stable, constant, absolutely measurable phenomenon though. You can divide it into whatever arbitrary or non-arbitrary units you want, but that system of measurement is still based on an absolute standard.
It’s like saying that we now define one year as 1.234 earth revolutions around the sun. Or 2. Or whatever. Arbitrary units perhaps, but still based on an absolute phenomenon.
If you really want to throw a wrench into this whole concept though, mention that the earth’s rotation is slowing ever so slightly over time… so we have to add time on to the atomic clock to attempt to sync it better with the earth’s non-linear rotational velocity. Who’s arbitrary now?! 😀
I believe that was because at the time of its discovery, that was the most accurately we could measure it. It’s still based on a stable, constant, absolutely measurable phenomenon though. You can divide it into whatever arbitrary or non-arbitrary units you want, but that system of measurement is still based on an absolute standard.
It’s like saying that we now define one year as 1.234 earth revolutions around the sun. Or 2. Or whatever. Arbitrary units perhaps, but still based on an absolute phenomenon.
If you really want to throw a wrench into this whole concept though, mention that the earth’s rotation is slowing ever so slightly over time… so we have to add time on to the atomic clock to attempt to sync it better with the earth’s non-linear rotational velocity. Who’s arbitrary now?! 😀