A star that has exhausted its fuel falls into itself. Its outer layers fly apart, while the core compresses to unimaginable densities. It was once thought that this process ends in a point — a singularity where the laws of physics break down. New work shows that just before the very end, something strange happens inside the future black hole. Space, which until then had obediently contracted along with matter, suddenly 'breaks'—it stops resembling familiar emptiness and begins to behave like an elastic medium.
This moment is dubbed 'Minkowski breaking,' after the empty space without gravity. Imagine a sponge squeezed from all sides. While it is wet and soft, it compresses easily. But at some point, the water is squeezed out, and the sponge becomes stiff — further pressing is nearly impossible. Similarly, when the inner horizon of the black hole vanishes, quantum effects stop hiding and begin to repel matter with tremendous force.
To describe this process, the scientists used two approximations. One for energy-momentum, the thing that presses and bends space. The other for the infalling matter itself, where its motion resembles a fluid flow with quantum corrections. It turns out that after 'Minkowski breaking,' an additional term appears in the main equation describing collapse — the quantum potential. And it doesn't just slow the collapse; it actively opposes it.
This work is another step toward understanding how quantum mechanics and gravity coexist in the most extreme conditions. Perhaps the singularity is not an endpoint but a door to new physics, where space and matter behave in ways we never imagined.
as written by the authors arXiv:2605.01808
Schwarzschild black holes are expected to emerge as the end states of the classical gravitational collapse from non-singular configurations. After integrable curvature singularities appear, the interior geometry can be modelled to exhibit a transition, called ``Minkowski breaking'', when the inner horizon disappears, before all matter collapses into the central singularity. This picture implies a quantum framework to describe the final stages of the gravitational collapse, and here we will provide more insights from the semiclassical approximation for the energy-momentum tensor and the Madelung approximation for collapsing matter. In particular, we will show that the quantum potential in the Raychaudhuri equation starts to strongly oppose the collapse towards the Schwarzschild singularity precisely after the Minkowski breaking.
The name 'Minkowski breaking' refers to mathematician Hermann Minkowski, who first realized that space and time form a single stage on which all events unfold. Inside a black hole, that stage cracks.
In Stanisław Lem's novel 'Solaris,' the planet's ocean behaves like a quantum fluid capable of altering the structure of space — a perfect illustration of the quantum potential that repels matter inside a black hole.