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Meta Research Bulletin ©2007
[1] Derivation note added 2000/05/15: Let 
and 
. When both masses are significant, the mutual orbit is
an ellipse, and each mass orbits their common center of mass in a smaller
ellipse. The pericenter motions of these smaller ellipses combine to give the
pericenter motion of the mutual orbit. The position and velocity of body b relative to body a for the mutual orbit 
both get scaled
by 
to get the
corresponding values relative to the center of mass, and the position and
velocity for body a relative to body b
on the mutual orbit 
both get scaled
by 
to make them
relative to the center of mass. However, the periods and average angular
velocities of both bodies in their separate orbits must remain equal to those
in their mutual orbit, so 
even while the
semi-major axes of the separate orbits are scaled the same way r is. It then follows from Kepler’s law (
and 
as applied to
each body separately) that 
gets scaled by 
and 
gets scaled by 
. Finally, pericenter advance is proportional to 
and 
for the two
bodies, respectively. Therefore, the sum of the two pericenter advances is
proportional to 
, which leads immediately to the scale factor in the
text.
[2] Note
added 2000/05/15: When analyzing binary pulsar data to test this prediction, it
must be remembered that similar scale factors may change predictions for other
related effects such as light-bending and gravitational radiation.
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