#### NotEinstein

**Valued Senior Member**

OK, then let's get back to more important things!Believe that if you wish - that particular issue is dusted and done as far as I'm concerned.

Do you have, or can you please link to, a mathematical derivation of this?It's quite straightforward. While from a coordinate basis the radial spacing of transverse grid lines compress closer to the source mass, radially oriented ruler shrinks by exactly the same fraction. The two cancel at any given radial location. Hence a 1cm proper radial displacement at one elevation is always transmitted as a proper 1cm radial displacement at any other elevation (we ignore 'practical' matters like mechanical stress/strain, and of course that elevations are always above the dreaded 'EH').