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 🤯
The Frensh-German TV-Channel Arte published a Documentary about the theorem, that we are probably living in a black hole. According to them its based on the work of Nikodem Poplawski (mathematician and physicist). It was a kinda nice theory and seemed appealing. But Im no scientist and I have no idea about higher Math and Physics. Sadly, on the German Arte-TV-Site the video is not avaible anymore. (According to German Law public-TV-Channels arent allowed to keep their Videos up online unlimited) https://www.arte.tv/de/videos/101940-002-A/leben-wir-in-einem-schwarzen-loch/
But I assume there are other sources, probably even in other languages.