Could anyone give me a descriptive picture on WHY geodetic precession occurs? I understand the equations from which it follows, so I can derive it algebraically, but I would like to get an intuitive feeling of why it occurs too. My problem is the following: parallel transport of vectors along a curved line (i.e., NON-geodesic!) results in the vector changing its orientation with respect to the line. Examples: (1) vector on a 2D Euclidean plane parallel transported along a curve; (2) vector parallel transported along a line of latitude (other than the Equator!) on the spherical surface of Earth. [This is the reason why Foucault's pendulum changes its orientation with respect to the laboratory on Earth (except on the Equator) as it rotates through 2Pi in a day.] However, as is also well known, if the vector is parallel transported along a GEODESIC line (e.g. straight line on a 2D Euclidean plane or the Equator on the spherical surface of Earth), it KEEPS its orientation with respect to the line along which it was parallel transported. I am confused, then, as to WHY the orientation of a gyroscope which is orbiting Earth (i.e. floating FREELY, i.e. moving along a GEODESIC) changes. Could anyone help me out? As I said, I'm looking for an intuitive answer (preferably using a geometric picture), rather than the algebraic derivation.