Re: So we've gone from six to five
apparently, a kibble balance can be used to measure Planck's constant.
Also I'd think it would require a VERY accurate definition of 'Ampere'.
And if any two SI standards are recursively/mutually dependent (because of measurement techniques, etc.), could a converging solution be used to make them as accurate as possible?
(I'd really hate for our measurement standards to end up as one big Catch 22 or chicken/egg paradox)