Newton's 3rd law? was Re: inertial forces (definition)

[Cliff Parker <cparker@EMPOWERING.COM>]

Leigh Palmer wrote:

> Today we understand that Newton's third law doesn't hold for
> gravitational forces. (There is no body on which you exert a
> force which is equal in magnitude and opposite in direction to
> the force of gravity which acts on you, even on a nonspinning
> planet.) One must inject the intermediary of a field (which is
> not a body) to save a semblance the appearances.

I am surprised by this statement.  Would you please expand on this idea?  I
have been teaching my students that they attract the earth as the earth
attracts them.  If I am teaching wrong ideas I would at least like to know
why the idea is incorrect.  Are you saying that field theory replaced
Newton's gravitational force theory, just as general relativity replaces
both?  I am not thoroughly versed in field theory but have thought that it
was an alternative to the idea of a gravitational force but not necessarily
superior.  Can you briefly tell me why field theory is superior to Newton's
theory?

Cliff Parker