Richard Clark wrote:
Einstein having "changed" what "is" understood of gravity from Newton's
teachings does not invalidate Newton's work

I entirely agree, Richard! (Don't be too surprised :-)

By quantifying the errors in Newton's original 'laws', Einstein actually
*confirmed* that Newtonian mechanics are valid for everyday situations.
The only way Einstein could have found that out was by exploring beyond
Newton, and then looking back.

That's exactly what we're trying to do with the present discussions
about lines with reactive Zo. We're trying to quantify the errors in the
formulae and definitions that we normally use, and we can only do that
by exploring beyond them... very carefully.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek