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This is one of the more popular misunderstandings of general
relativity, that it implies gravity is a fictional force loosely akin
to the centrifugal force (he said with trepidation). It is an easy
idea to acquire since the GR notion of gravity is so strange but it
is not quite correct. The gravitational force is perfectly real BUT
it is nonlocal. At a point, it is not measurable. Compare one point
to a point some distance away and then you can see the effects of
gravity.
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... This also gives me a chance to clear up a slight oversimplification
that has cropped up in this thread and is complicating the discussion
-- the notion that a free fall frame is an inertial frame in
relativity. It is not. It is LOCALLY an inertial frame but it is the
mismatch between free fall frames for separated observers that
constitutes spacetime curvature and so gravity.
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