Wayne.B wrote:
On Thu, 22 Feb 2007 20:13:10 GMT, Short Wave Sportfishing
wrote:

No. It induces a wobble in the larger object. That's how NASA, Ames
and JPL do those extra solar planet searches with the Spitzer X-Ray and
Hubble telescopes - they look for the star wobble and aim for where the
planet should be based on the arc of the wobble.

The barycenter is the barycenter - the center of mass of any system of
objects.

I understand your point if taking a distant view from outer space.

At close range however the moon is revolving around the earth, and the
earth is spinning on its axis. That says to me that the geographic
position of the barycenter is constantly shifting with respect to the
earth's surface.

Hmmmm - I guess you could put it that way in terms of geography. You
could also say that the Earth is spinning around the barycenter.

For example, it you had two bodies on the same plane orbiting each
other, the barycenter is located in space between the two - it doesn't
move as long as the masses are balanced by the mechanical motion.

Or take another case. Say you have a large rotating body around which a
smaller, but massive body rotates. The barycenter is just above the
surface of the larger body. The barycenter never changes position - it
is the balance point, but the structure below it changes.

Good God, I haven't worked with these concepts in ages. I have a
headache. :)