First off, I will state that this topic has absolutely nothing to do with the real world. However, I think it does still have to do with physics. Though, if the mods think this should be moved elsewhere, feel free.
The details of where this question comes from aren't particularly important, but the question has been bugging me for a while. I'm trying to figure out how to make a consistent set of astrophysical rules for how a set of spheres can move around each other when none of them are in the center of motion. Obviously, this isn't constrained by real world considerations, such as gravity, or at least, not exactly.
The main constraints I'm working with are that none of the spheres should crash into one another, but things should still move around (it's no fun if things just spin in place). While real gravity certainly covers this, it's much too chaotic for what I had in mind.
Another thing to point out is that there are three types of spheres. I'm calling them stars, planets and black holes, but they're all about the same size. The stars aren't hot, just bright, and the black holes don't necessarily have more pull than any other sphere. They may or may not behave differently; I haven't really decided.
So far, the best I've come up with is to have each sphere moving around in a circle, but without some logical center for the circle, that doesn't really make much sense.
(And William, before you say anything, just because it's fantasy doesn't mean logic and reason have no place. It's called verisimilitude, and in my opinion it's an important part of any work of fiction.)