That’s still arbitrary. The definition is just something that gave a result that was a useful scale for humans. There’s no reason to pick that over, say, the average distance to the moon, or something else. That distance is just fairly easy to measure and reasonably consistent over time. There are other choices for it though. The 1/10,000,000 is just whatever number was needed to make it useful. Nature doesn’t care about that distance, unlike the speed of light.
Comment on Fictional
turdas@suppo.fi 18 hours agoThe meter isn’t really arbitrary, even when you ignore the description by @jumperalex. It was originally defined as 1/10,000,000th the distance from Earth’s pole to the equator, which is a pretty reasonable basis to use by 1791 standards.
Cethin@lemmy.zip 15 hours ago
turdas@suppo.fi 14 hours ago
Nature doesn’t care about anything. It is not a conscious thing. The size of the Earth, however, is a natural phenomenon, just like the speed of light. It just isn’t a universal constant, relatively unchanging though it may be.
A multiplier is obviously going to be necessary whatever the base measure, because there’s no universal constant that happens to be of a useful, human scale. Or I guess you could use something like the wavelength of the hydrogen line – about 21.1 cm, a fairly useful length – but that isn’t really inherently a special wavelength, it just happens to be useful in radio astronomy.
Cethin@lemmy.zip 12 hours ago
The specific chosen points to measure are not natural. The size of the earth is relative to where you pick those points. Sure, it is natural that those two points exist, but choosing them isn’t. Any two points any the universe exist naturally. Picking two points to measure is not.
Yeah, to make it useful to humans it needs a scaler. No one is saying that isn’t true. That doesn’t make it any less arbitrary.
SpaceNoodle@lemmy.world 18 hours ago
That’s pretty damn arbitrary on a universal scale
BC_viper@lemmy.world 17 hours ago
Everything is pretty arbitrary on a universal scale. Except the speed of light. Which is really fucking slow on a universal scale too.
SpaceNoodle@lemmy.world 16 hours ago
But not arbitrarily.
turdas@suppo.fi 17 hours ago
True, but it was the 18th century. They could measure earthly things well enough, not so much photons.
It’s a bit of a shame it wasn’t redefined as 1/300,000,000th of the distance light travels in a second when it was redefined, but the redefinition was about 50 years too late for that to happen. A difference of 0.07% in the base unit of measurement used by all science would’ve been far too much for 2019, given all the precision measurements we do these days.