Black holes are regions of infinite density, known as a singularity. And according to mainstream physics, each of these cosmic matter munchers is fringed by an event horizon –- a boundary where once you fall in, you never come out.
But what if some black holes are naked — completely lacking such frontiers? As far as we can tell, singularities are always wrapped in event horizons, but a more detailed look at the math of general relativity suggests that doesn’t have to be the case.
If such naked black holes dot the universe, new research reveals how we might be able to detect one: by looking at the ring of light surrounding it.
Related: What’s inside a black hole?
‘The Emperor Has No Clothes’
Black holes are a consequence of the mathematics of Einstein’s theory of general relativity. Those equations tell us that if a clump of matter collapses