Comment by avmich
4 days ago
> But how come Penrose’s theorems forbid out such outcomes? It’s all down to a rule called the quantum exclusion principle, which states that no two identical particles known as fermions can occupy the same quantum state (such as angular momentum, or “spin”).
> And we show that this rule prevents the particles in the collapsing matter from being squeezed indefinitely. As a result, the collapse halts and reverses. The bounce is not only possible – it’s inevitable under the right conditions.
Then how comes the neutron stars collapse into black holes despite obeying the exclusion principle?
Then how comes the neutron stars collapse into black holes despite obeying the exclusion principle?
Different exclusion principle. For neutron stars, it is the Pauli exclusion principle (IIRC) which creates neutron degeneracy pressure. Enough mass and gravity can overcome it forming a black hole. The article is talking about quantum exclusion which happens at a much smaller scale. I don't know much about it because that exceeds the limits of my degree.
>Then how comes the neutron stars collapse into black holes despite obeying the exclusion principle?
One of the ways to overcome one of the levels of this degeneracy pressure is electron capture which is the opposite of a kind of beta decay. Squeeze hard enough and a proton combines with an electron to form a neutron and a neutrino.
But there are several proposed levels of degenerate matter in neutron stars, the idea being that one (final?) level of this degenerate matter is dense enough to make an object smaller than its schwarzschild radius. Uncertainty is high because we have no current methods to observe any of this kind of matter.
What goes on inside the schwarzschild radius is another mystery we don't have answers from, but there are lots of ideas with various levels of legitimacy.
Quantum physics in and around singularities or things we think are singularities is not understood.
Is it because the black hole is a macro distortion of spacetime and not a local quantum property?
With enough mass, there is enough energy from gravity to put all fermions into different states, so the collapse continues
Are you suggesting that the authors’ “bounce” would only happen if the energy was not enough to put them into different states?