The idea that we might be living inside a black hole is a serious scientific hypothesis explored by some physicists and cosmologists. According to a recent theory, our entire universe could be the interior of a black hole that formed in a "parent" universe. This suggests that what we perceive as the Big Bang was actually a "bounce" or rebound from the collapse of an earlier universe into a black hole, and this process could be cyclic, leading to an infinite series of universes arising inside black holes.
This theory is grounded in Einstein's general relativity and quantum mechanics principles, such as the Pauli exclusion principle, which prevents a complete collapse into a singularity, allowing the universe to expand anew inside the black hole. Different stages of the universe's expansion, including inflation and dark energy, are explained within the dynamics of this rebound. Such a model is testable and might be verified by upcoming space missions.
However, there are also arguments against this idea. For instance, the uniform expansion of our universe, the cosmic microwave background radiation, and the absence of an observable event horizon around the universe point to differences from what is expected inside a black hole. Our universe's large- scale structure and isotropy do not fully match the extreme gravitational conditions and singularity expected inside a black hole.
In summary, while it is a plausible and mathematically interesting hypothesis that the universe might reside inside a black hole from a larger parent universe, it remains an open question without definitive evidence so far. The theory challenges traditional views of the Big Bang and cosmic origins, offering a fascinating alternative perspective on our place in the cosmos.