Black holes are about the worst subjects for direct study in the universe. But at this stage, it’s all we can do to convince ourselves of their existence. Actually studying the physics of real black holes is much, much harder. I mean, we could try to make one - but that’s way beyond our current tech level, and also potentially humanity-destroying. Well it turns out we don’t need to make real black holes to at least get started with the lab work. We can instead study analog black holes - and by analog, I don’t mean old fashioned clockwork black holes - I mean analogies. Physical systems that aren’t black holes but that behave in similar ways - and may reveal the real behaviours of real black holes.