The entirety of the concept/thought experiment is absolutely flabbergasting. I’ve read tons of material available on this subject and it just keeps getting more incredible. The three dimensional portion of our universe expanded faster than light travels through it, so we can never see past a certain point. I’ve come to picture matter in our universe as three dimensional energy protrusions from what I call “The multidimensional pure energy substrate”. There isn’t truly anything “physical/solid” in our universe. Imagine protons, neutrons, and the electron clouds as energy fields protruding from an “infinitely” small point we can also call an event horizon. I picture every atom and force in our universe as a bubble/foam on the surface of boiling water (The multidimensional pure energy substrate). To me, black holes, are an example of how energy protrusions into this 3 dimensional “blister” naturally try reabsorb into the multidimensional substrate.