Black holes are already mind-bending enough. Matter and energy compressed into a region so dense that the escape velocity exceeds the speed of light. Places where space and time are tangled up so much that even if you could go faster than light speed, you’d still end up at the singularity. Astronomers know of two kinds of black holes in the Universe: stellar mass and supermassive, and how we get them have been worked out pretty well. Primordial black holes.