> These [baby] universes would be unobservable to us because they are also behind an event horizon, a one-way light-trapping point of no return from which light cannot escape, meaning information can never travel from the interior of a black hole to an external observer. Also meaning that “our” blackhole (the one containing us) is unobservable from the parent universe for the same reason. So where is all this extra l…
(Complete hypothesizing from a very cursory understanding.) Perhaps that's dark energy or vacuum energy? If mass and time truly switches places when crossing into a black hole, it would make sense that the spacetime size of this universe translates into observable mass outside it. Which might tie it to the expansion of the universe.
What do you mean by that?