According to The Conversation, a new study published in Physical Review D challenges the common idea that the Big Bang was the start of everything. Instead, researchers suggest it might have been a rebound—a bounce—after a huge gravitational collapse forming a black hole.
This “black hole universe” idea uses everyday physics to rethink cosmic origins. Instead of starting with expansion and tracing back to a mysterious singularity, the model looks at what happens when a large mass collapses under gravity, similar to how stars become black holes. But unlike the sharp singularities predicted by classical physics, this model uses quantum mechanics to show that the collapse doesn’t go on forever.
The bounce is driven by the quantum exclusion principle, which prevents identical particles, such as fermions, from being squeezed into the same quantum state. As a result, the collapse hits a limit and then reverses, causing an outward bounce. According to the research team, “the bounce is not only possible – it’s inevitable under the right conditions.”
The model explores a spherical collapse of mass M with an initial size χ_* inside a curved region defined by k ≡ 1/χₖ² ≤ 1/χ_²*. The material inside is treated as a perfect fluid that shifts from pressureless dust (P = 0) to a stable energy density ρG over time. This leads to a bounce at: R_B = (8πGρG / 3)^−1/2
After the bounce, the universe goes through rapid expansion, with the pressure P(ρ) acting like an inflation potential—similar to how standard cosmology describes early universe inflation and today’s dark energy.
The model also predicts a small but noticeable positive curvature in space: −0.07 ± 0.02 ≤ Ωₖ
Interestingly, the bounce happens inside the gravitational radius r_S = 2GM, which acts like a cosmological constant Λ from within. Outside, it still looks like a normal Schwarzschild black hole.
Future missions such as Euclid could test the predicted curvature. Other projects, like Arrakihs, will study faint features including stellar halos and satellite galaxies, possibly tied to ancient compact objects like black holes that made it through the bounce.
In this view, the Big Bang wasn’t the birth of everything—it was the start of a new cycle inside a black hole formed in a larger universe. As The Conversation puts it: “We are not witnessing the birth of everything from nothing, but rather the continuation of a cosmic cycle.”
Source: The Conversation, American Physical Society
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