Quadibloc wrote:

On May 13, 1:33*pm, Dave Typinski wrote:

Third, using your new big G number, calculate the Earth mass required
to produce the measured orbit altitude and period.

And then you compare it with a known value for Earth's mass,

Why compare it to anything? If you have the local acceleration due to
gravity, and you have G, you can calculate the mass required to set up
a gravitational potential field necessary to cause the acceleration
you measured.

determined by core samples of the Earth's crust, mantle, and core? I
didn't think we had the latter two yet.

Inferred from seismic analyses, aren't they? Whether they're known or
not, I don't understand why this would matter. The distribution of
mass within the Earth will make a difference to the gravitational
potential field interior to Earth's surface. External to the surface,
it's a point mass with corrections for centripetal acceleration and
surface altiutude deviation from an ideal ellipsoid.

Or am I missing your point entirely?

Actually, though, you _are_ right that the reasoning is not circular,
but not for the reasons you've outlined.

Think of satellites in polar orbit.

You've stumped me, John. How does changing the orbit inclination
simplify things make the reasoning non-circular?
--
Dave