For every activity there is a center, like the vortex of a whirlpool or the yolk of an egg. Usually there is an orbital (or at least a fixed) path associated with the surrounding particles. The center not only provides the centripetal force which is necessary for orbital motion but sometimes has other very important functions to perform. For example, here's an article which states that the nucleus is really the living cell's mothership, a crucial and very active source of information, support and control.
Though not exactly orbital, blood circulates in the body following a fixed path, going through the heart. The heart is the center and the only instance when blood violates its definite path is when bleeding occurs.
The orbital motion is very prominent in the electrons tied to every atom's nucleus; the moon of every planet; the planets of every sun, etc. Not surprisingly, Muslims perform a circular ritual around Ka'aba during Haj. This center of all the activity has to be practically demonstrated at least once in a lifetime.
If something breaks its designated path, it goes astray. The suns and moons are very obedient creations (some people would like to replace the word obedient with dumb). But man has been given choice, which unfortunately is a very complex topic. The life of a human being can revolve around many centers. Or in other words, the center keeps shifting. To realize/ recognize our true center is the first and foremost duty.
A long time ago, PTV telecasted a very good drama with the title, "2 Suraj ka Siyara" (which translates into A Planet of Two Suns). Are you a planet of more than one sun?
"I am a trafficker of information, I know everything I can. The question is, do you know why you are here?"
(Merovingian: The Matrix Reloaded)