Missing Milky Way black holes are bad news for this dark matter theory

A blue sphere with a cone of white extending from it leading to a reversed cone of a cloud of blue and purple strands.

Scientists have found that unusually massive black holes seem to be absent from the diffuse outer halo of the Milky Way. 

The discovery could spell bad news for theories that suggest the universe's most mysterious form of "stuff," dark matter, is composed of primordial black holes that formed in the first moments after the Big Bang.