Black hole cosmology suggests that the Milky Way and every other observable galaxy in our universe is contained within a black hole that formed in another, much larger, universe.
The theory challenges many fundamental models of the cosmos, including the idea that the Big Bang was the beginning of the universe.
It also provides the possibility that black holes within our own universe may be the boundaries to other universes, opening up a potential scenario for a multiverse.
Mine blown 🤯
Surely at some point it stops being useful to apply the same terminology to such vastly different concepts. If the universe is a black hole and Sagittarius A* is a black hole then “black hole” doesn’t communicate anything effectively outside of extremely niche astrophysics conversations.