New Maps of the Chaotic Space-Time Inside Black Holes
29 comments
·February 25, 2025achille
pdonis
In the GR model of black holes, the singularity is at the end of time inside the hole, not the beginning.
JumpCrisscross
> my understanding was that this was disproven
To the extent anything in this discussion can be absolute, it's the wrongness of your statement. Nothing about singularities has been empirically proven (or disproven).
ziddoap
PBS Space Time's take on Kerr's paper:
https://www.pbs.org/video/what-if-singularities-do-not-exist...
Echoing JumpCrisscross' sentiment, though. "Disproven" is way too strong of a word.
mr_mitm
They are singularities in the framework of general relativity, i.e. while ignoring quantum mechanics. I think most people expect the right version of quantized gravity to make the singularities go away, but studying classical GR is worth it on its own, so it's often ignored like in this statement you quoted.
goatlover
What if gravity is non-linear and thus collapses the wave function? I think Penrose has suggested gravity as an objective collapse interpretation. The measurement problem still hasn't been resolved, but we observe a classical world around us, despite the fact that decoherence simply spreads the superposition of interacting quantum systems to the world. Gravity could be what prevents the linearity of quantum systems from putting the entire universe into superposition.
biimugan
Your first link goes to a 2023 arXiv pre-print that never landed in any journals as far as I can tell (could be wrong though). And there seems to be some controversy about whether Kerr's math shows what he says it shows.
This is the danger of trying to sensationalize science and putting any special weight on science influencers, especially ones who very often seem gung-ho about any story that challenges the status quo despite the evidence.
monocasa
To be fair, it's written by literal Roy Kerr.
null
spwa4
Layman opinion here: If a black hole forms, the point where it forms is an event horizon, but not a singularity. Then, while things get worse, it disappear from the universe.
So why would a singularity ever form? And what can't be formed, can't exist.
mr_mitm
Cosmologist here, the event horizon is not a true singularity. There is a singularity in certain coordinates, but it goes away when doing a coordinate transformation. There is nothing physically strange going on at the event horizon. The physical singularity is only at the center.
rbanffy
I have the (layman) impression that there is no inside - that spacetime is so stretched around the event horizon that there is no spacetime beyond it.
But, then, I've never seen anywhere that the mass of the black hole (which is very much a real thing that exists in spacetime) is distributed over the event horizon, which would be at the biggest amount of mass a given region of spacetime can hold, and is not concentrated on a point with infinite density inside it.
nh23423fefe
black holes have an interior, you wouldn't notice if you passed the event horizon of a large enough black hole.
empath75
Sabine doesn't even say it's disproven, and the paper doesn't claim that it's disproven, it just claims that one of the earliest proofs that it was a singularity was incorrect. There's an important distinction there. If someone points out a flaw in a proof of the pythagorean theorem, that doesn't mean the theorem is disproved, it just means that the proof was wrong.
uoaei
A more diplomatic and uncontroversial way to put it is that the event horizon is the only thing we have any evidence for.
oneshtein
Two event horizons, because gravitation cancels out in the center of a black hole.
ps. Energy is sucked up from the center by second event horizon, but matter is pushed inside, forming a dense and cool crystal, a solid foundation for second order effects to play.
uoaei
That assumes there is gravity, or even universe, "inside" the black hole. We don't have any evidence of that.
stefantalpalaru
[dead]
ck2
trying to find the PBS Space Time for that but meanwhile enjoy
> "At the beginning of time and the center of every black hole lies a point of infinite density called a singularity"
my understanding was that this was d̶i̶s̶p̶r̶o̶v̶e̶n̶ mathematically incorrect:
- https://news.ycombinator.com/item?id=38636225
- sabine's take: https://www.youtube.com/watch?v=nz55jONtFAU
edit: disproven -> mathematically incorrect