system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: I read that each black hole can produce its own universe and that ours can be spawn from a black hole as well. Can someone explain this? Where does the energy come from to produce an entire universe?

For example if a black hole in our universe spawns a universe, would the universe have the same energy as ours?  How can this be possible? Where does the energy come from?
gpt
That's entirely hypothetical and theres no direct evidence for that. We still don't know how black holes work at the quantum level. We need a unified theory of quantum and classical mechanics before we can join the dots and work out whats really going on inside a black hole.

For now though there's lots of theories about what happens inside a black hole, some more credible than others.