Admittedly, for yet another science-fiction project
Say I have a planet-like body shaped like a sphere with a torus subtracted out of it, leaving a sort of "apple core" shape.
Firstly, is the structure gravitationally stable, or would it collapse in on itself?
Mainly, I'm trying to assess the dynamics of gravity on the body, as there might be cultures on the outer (top and bottom) surfaces, on the torus-subtracted surfaces (the eaten flesh of the apple), and inside the lobes of the body, living in tunnels and caves bored into the crust.
To me, it seems that there are three basic ways this could go:
In scenario A, the gravity is still roughly similar to a spherical planet, with the two lobes interfering with each other to create a balance point in the center. In scenario B, the acceleration is focused towards the two lobes, but there's more of a "dead zone" where the gravity of the two lobes cancels each other out. Scenario B seems to act slightly more like a two-body problem. In Scenario C, the lobes are even more dominant, and they exert little stress overall on the central spindle. I figure this is more likely if the thing is rotating about its center, but NOT from top to bottom, so that the poles are sticking out from the eaten sides of the apple.
Questions relating to how the gravity of such a body would function: Would all the liquids (oceans, atmosphere) slip right into the torus rift, or would some of them stick to the top and bottom? Is the gravitational situation related to the size of the object (in that with a smaller object, the lobes would be close enough to influence each other more gravitationally)?
I apologize for my rudimentary physics knowledge.