[Proj] Fw: Re: GeographicLib geoid calculations

[J Luis]

> The geoid might be an interesting academic study but the ellipsoid is
> a much more stable zero reference and since the earth is not stable
> by its nature (plate dynamics) it is obvious that the geoid will never
> be fully fixed in time.

Academic?
The water flows down the geoid, NOT the ellipsoid.
Te ellipsoid is not fixed in time either, if not for isostasy an land
masses erosion,  sea level changes.

Joaquim