The idea that our entire universe exists within a black hole is an intriguing concept that has been explored in theoretical physics. However, it remains a speculative idea without conclusive evidence at this point.
The notion stems from the mathematical work on black holes and attempts to reconcile general relativity (which describes gravity on large scales) with quantum mechanics (which governs the behavior of particles on small scales). In particular, some researchers have explored the possibility that our universe could be a "baby universe" formed within the singularity of a larger parent black hole.
This idea is related to the concept of black hole thermodynamics and the holographic principle, which suggests that the information within a region of space can be encoded on its boundary. According to this line of thinking, our three-dimensional universe might be encoded on the two-dimensional surface of a black hole.
However, it's important to note that these ideas are still highly speculative and are the subject of ongoing research and debate. Our current understanding of black holes and the nature of the universe is based on a combination of empirical observations and theoretical models, but we have not yet obtained direct experimental evidence or a complete theory that can definitively confirm or reject the notion of our universe existing within a black hole.
Scientific understanding is continually evolving, and it is possible that future discoveries and advancements may shed more light on this intriguing idea. However, for now, it remains an intriguing but unproven hypothesis.