Can a single galaxy support two mid-sized black holes? This one does. This composite image shows the starburst galaxy M82, with two intermediate-sized “survivor” black holes that have managed to avoid ...

Two colossal black holes among the most massive ever seen collided in deep space, creating gravitational waves that rippled across the cosmos and shook the foundations of astrophysical theory.

Whenever someone talks about black holes, they almost always talk about the event horizon and the singularity. After all, that's what defines a black hole, right? Well, it depends on what you mean by ...