You're pretty smart ...I bet, you're a 10th level Dungeon Master ...<quoted text>
True. But we have candidates. We just need data to test between them. ALL are quantum theories..
This depends a bit on what you mean by 'understand'. We have incredibly good descriptions of both electricity and gravity as parts of predictive testable theories.
The main problem we have with event horizons surrounds the question of quantum gravity. Once again, we have candidates, but need data to test them.
More accurately, we have *found* dark matter and dark energy, but are trying to determine what they are made from. For dark matter, there are several good candidates, but once again, we need *data* from the particle physics crowd to test between them. Dark energy is another beast--we understand very little about it as yet.
That said, none of this directly impacts what Bob said (although the details of dark energy could do so).
Mankind has nothing to do with it. There are two different settings where 'multiple universes' come up in modern physics: the first is the 'many worlds' interpretation of quantum mechanics, where the wave function of the universe can be *interpreted* as splitting into separate, branching universes at each quantum event. The second is in the context of a multiverse where different universes 'pinch off' from the main deSitter space via quantum fluctuations. Neither has anything to do specifically with mankind. The first has to do with quantum events and decoherence, while the second is more a description of how universes form.
..NO..We use electricity , we create and store it , even..But, we don't know why , certain materials make the electrons flow ...As, for gravity ..pffft , We can't even say ,are we being "pushed" or "pulled" ..???
I'm inclined to believe , "you" really don't think we know how or why the universe behaves as it does ...nor ...do "you" believe we have really plumbed any of its secrets ...