Measurement of singularity as a particle inside event horizon

nomadreid
Gold Member
Messages
1,748
Reaction score
243
Although the subject line might seem to put this question inside general relativity, the reason I put it in quantum physics is because I would like to know what happens when one treats a singularity as a particle. Obviously from outside the event horizon, one cannot do this, but inside the event horizon the situation is different. Nonetheless, if anyone thinks the thread should be moved, I would have no objection.

I know that the current physics largely breaks down at the singularity, but assuming that some sort of physical laws will eventually be formulated that can deal with the presence of the singularity, the first question which arises is that of measurement.

Inside the event horizon, a direct measurement of the singularity by bouncing photons off of it would be impossible. However, the behavior of photons and other particles around the singularity would be measurable: could these provide a means for an indirect measurement of the singularity?

If a measurement is indeed possible, what would be the status of the uncertainty principle? Is the fact that σx =0 give an absurdity for σp or does it just mean that we cannot know anything about the momentum? Wouldn't there be any finite bound on the spectrum of the momentum?

Although outside the event horizon we can know the mass of the black hole, an observer inside the event horizon could not measure the size of the event horizon to get the mass, right? At best an observer could measure the mass from outside, then enter the event horizon and assume that the mass had stayed the approximately the same within certain bounds. Would this be valid?

(To forestall the obvious: the observers would obviously not be human.)
 
Physics news on Phys.org
You could, in principle, get a human of free-fall past the event horizon of a super-massive black hole without being torn apart.

You question amounts to what an in-falling observer would be able to see as the singularity is approached.
i.e. as concerns other infalling objects.

Definately not QM.
 
  • Like
Likes 1 person
Thanks, Simon Bridge.
Oops, I forget how to move this thread to a more appropriate topic (General Relativity): it's not in "Thread tools", and this does not seem to be covered in "Help". I don't find any other relevant buttons to click. Help?
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!

Similar threads

Back
Top