There are multiple ways to form black holes. The one most commonly taught in high school physics classes is that they are created from the collapse of a dying star. But there are another class of black holes, known as Primordial Black Holes (PBHs) that could have been created immediately after the Big Bang by matter collapsing in on it. Or that’s the theory at least. Though long theorized, we’ve never actually seen one of them, though scientists have suggested that they might account for the missing mass of the universe, which we otherwise describe as “dark matter”. But a new paper, available in pre-print on arXiv from researchers at Oakland University in Michigan and Rice University in Texas, calls that theory into question, at least for a certain type of PBH.