3 ms·
Four of the seven physical constants used to define the seven base SI units will change, so a bunch of physical constants that currently have exactly defined va
by ramshorns 9y ago
Four of the seven physical constants used to define the seven base SI units will change, so a bunch of physical constants that currently have exactly defined values will start being subject to measurement uncertainty. So μ_0 will no longer be exactly 4π × 10^-7 H/m, k_C = 1/4πε_0 will no longer be exactly 8,987,551,787.3681764 N m^2/C^2, and 1 mol of carbon-12 will no longer have a mass of exactly 12 g.
- Jyaif 9y agoWhy can't they update the Avogadro constant and keep having 1 mole weight 12g of carbon 12?
- deleted 9y ago[deleted]
- spiralganglion 9y agoAnd for that matter, isn't it a bit frivol to call it a constant, if it's based on something mutable? Perhaps "the Avogadro number" would be a more appropriate name.
- hluska 9y agoI don't actually know what any of that means (this is either impostor syndrome or I'm just dumb), but it reminds me of why I love Hacker News so much. Now to Google to figure out what the heck you just said...:)