"Rick Sobie" wrote in message
news:md8Eb.745272$9l5.166726@pd7tw2no...

[snip]

Would it not be better then, to choose a unit of length,
which is in accordane with some fundamental measurement,
that is unchanging and more accurate?

Say the radius of the Hydrogen Atom at a certain temperature
- in its rest state for instance.

The Hydrogen atom does not have a sharply defined radius.
And even if it did, how would you propose to make use of it?

[snip]

Franz