[Physics] About the equivalence principle

[Ilja Schmelzer]

> When watching a piece of lead and a piece of wood fall, they appear to fall in
> exactly the same manner. They do not. The lead actually falls faster, but the
> difference in acceleration is so minute that it cannot easily be measured, and
> can be ignored for all practical purposes.

Fine. But this is not an error in GR.  Because it is well-known that
in the usual formulation you have used the Equivalence Principle is
only an approximation.  It applies only as far as the Earth can be
approximated by a constant gravitational field.  And, as well, only as
far as this field is not disturbed by the test particles considered.
So, if you have a mass of the size of the Earth, it attracts the Earth
itself too and distorts the issue.