It starts out OK enough, with basic talk about singularities and research by a Russian cosmologist. But then:
Dokuchaev’s research demonstrates that “living inside the eternal black holes is possible in principle, if these black holes are rotating or charged and massive enough for weakening the tidal forces and radiation of gravitational waves to acceptable level.” Type III advanced civilizations on the Kardashev scale that have achieved mastery of the resources of their galaxy, could inhabit such black hole interiors.
“We hypothesize that the advanced civilizations may live safely inside the supermassive black holes in the galactic nuclei being invisible from the outside,” writes Dokuchaev in his study.
Dude, that’s … that’s part of the backstory of Doctor Who. (Sorta)