Quote Originally Posted by OngBonga View Post
How do two objects with zero volume actually merge? I'm really struggling with the idea of a singularity, I suspect that all of the mass of a black hole is actually in orbit around it's common centre of mass. That's all the singularity actually is... the common centre of mass.

I like this hollow black hole idea. Beyond the event horizon is a perfect vacuum.
IDK. I suspect [some quantum force that we cannot directly observe because it only manifests at energy densities beyond an event horizon] prevents the formation of a true singularity, but I'm just speculating.

It could be even weirder. The axes on a spacetime diagram flip when you cross an event horizon. So on this side of an event horizon, we are free to move in any of our spacial dimensions, but constrained to only move forward in time. On the other side of an event horizon, we'd be free to move about in time however we like, but we can only move in 1 direction in space (toward the center of the BH). At least, that's what the math says... what that means or how it would be experienced is beyond me.

That center could always be infinitely far away for all I know. Expanding spacetime could mean that there is ever increasing distance between you and the center, despite you always moving toward it. IDK.