According to best calculations, there might be 10 million to 1 billion stellar-mass black holes floating calmly and silently around the galaxy. When it comes to counting them, there’s just one problem: they’re virtually undetectable until they manage to catch ...

A black hole’s structure is straightforward in the grand scheme of things. All you need to know is the black hole’s mass, electric charge, and spin to determine the structure of space and time surrounding it. However, things get complicated ...