so now the latest theory is that our universe is located on the "other side" of a black hole located in a "five-dimensional" universe, and that the big bang is actually the material falling from that universe into that black hole and exploding/creating this universe.
https://www.zerohedge.com/news/2019...e-live-gigantic-higher-dimensional-black-hole
https://www.zerohedge.com/news/2019...e-live-gigantic-higher-dimensional-black-hole
