[HN Gopher] New maps of the chaotic space-time inside black holes
___________________________________________________________________
New maps of the chaotic space-time inside black holes
Author : rbanffy
Score : 93 points
Date : 2025-02-25 16:15 UTC (6 hours ago)
(HTM) web link (www.quantamagazine.org)
(TXT) w3m dump (www.quantamagazine.org)
| achille wrote:
| > "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 disproven mathematically
| incorrect:
|
| - https://news.ycombinator.com/item?id=38636225
|
| - sabine's take: https://www.youtube.com/watch?v=nz55jONtFAU
|
| edit: disproven -> mathematically incorrect
| JumpCrisscross wrote:
| > _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).
| oneshtein wrote:
| We can empirically prove that gravitation cancels out in the
| gravitational center of an object, if we will dig into Moon.
| mr_mitm wrote:
| What does this have to do with singularities? No one
| expects any kind of singularity anywhere around or in the
| moon.
| oneshtein wrote:
| Singularity is not possible at 0G, isn't?
| JumpCrisscross wrote:
| > _Singularity is not possible at 0G, isn 't?_
|
| One divided by zero is a singularity. Singularity,
| mathematically speaking, means your math breaks. Calculus
| gets around this problem with limits. But there is
| absolutely nothing about physics that prohibits
| singularities, even gravitational singularities, in a
| zero G space because by definition a gravitational
| singularity _per se_ has an undefined G.
| oneshtein wrote:
| Singularity means that at least some barions will be at
| the same place in the same time, which against nature of
| fermions.
|
| Moreover, it hard to imagine that Higgs bosons will act
| at same place and time with same effectiveness.
|
| So, I cannot believe in a singularity unless it will be
| physically demonstrated.
| mr_mitm wrote:
| Sounds like you mean fermions. Bosons absolutely can
| occupy the same quantum states, look up the Bose-Einstein
| condensate.
|
| Also, no one serious claims that singularities exist when
| taking quantum mechanics into account. It's completely
| unknown territory.
| oneshtein wrote:
| I wrote <<barions>>, but yes, you are right, I meant
| <<fermions>>. Fixed.
| JumpCrisscross wrote:
| They're mixing up barycentres [1] and baryons [2].
|
| [1]
| https://en.m.wikipedia.org/wiki/Barycenter_(astronomy)
|
| [2] https://en.m.wikipedia.org/wiki/Baryon
| oneshtein wrote:
| Anyway, I propose to dig tunnel to the center of the Moon
| with plasma cutters and make a lab there. IMHO, the
| result will be worthy.
|
| As non-native speaker, it's hard for me to argue with
| native speakers (especially when I sick, tired, in army,
| and at war), and I refuse to use AI to translate, because
| I suspect that such messages will be automatically
| rejected by future archivists.
| JumpCrisscross wrote:
| > _Singularity means that at least some barions will be
| at the same place in the same time_
|
| The singularity in a black hole has no conception of
| baryons, hadrons or fermions. Those are quantum
| particles. The singularity is in general relativity.
|
| Also, 0G doesn't mean zero gravity. An object in freefall
| is still subject to gravity despite experiencing 0G.
|
| (Side note: fermions can occupy the same place at the
| same time. They cannot occupy the same state. This
| seeming mathematic fuckery goes on to describe many real-
| world weirdos like neutron stars.)
| credit_guy wrote:
| You don't seem to be new around here, so this quote from this
| forum's guidelines is more for the benefit of others
| > When disagreeing, please reply to the argument instead of
| calling names. "That is idiotic; 1 + 1 is 2, not 3" can be
| shortened to "1 + 1 is 2, not 3."
| JumpCrisscross wrote:
| You're right. My apologies to OP and y'all. Can't edit, but
| the snark was uncalled for.
| biimugan wrote:
| 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 wrote:
| To be fair, it's written by literal Roy Kerr.
|
| https://en.wikipedia.org/wiki/Roy_Kerr
| ziddoap wrote:
| 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.
| empath75 wrote:
| 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.
| spwa4 wrote:
| 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.
| rbanffy wrote:
| 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 wrote:
| black holes have an interior, you wouldn't notice if you
| passed the event horizon of a large enough black hole.
| mr_mitm wrote:
| 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.
| uoaei wrote:
| A more diplomatic and uncontroversial way to put it is that the
| event horizon is the only thing we have any evidence for.
| oneshtein wrote:
| _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 wrote:
| That assumes there is gravity, or even universe, "inside"
| the black hole. We don't have any evidence of that.
| oneshtein wrote:
| Occam's razor says that you must present a proof that
| they are not existing in a black hole.
| JumpCrisscross wrote:
| > _Occam 's razor says that you must present a proof that
| they are not existing in a black hole_
|
| Occam's razor absolutely doesn't predict that the weird
| thing that breaks physics occurs twice and then
| precipitates a crystal.
| oneshtein wrote:
| Physics is fine, it just model, which breaks.
|
| However, we can see that stars are eaten by black holes,
| and then can be partially released back years later, so
| it's proven that 1) <<an event horizon>> exists, 2)
| matter can pass the <<event horizon>> in both directions,
| 3) light cannot pass the <<event horizon>> in one
| direction.
|
| I do not introduce a new physics, like a <<singularity>>,
| without any evidence. Occam's razor is in my hands now.
| zardo wrote:
| > 2) matter can pass the <<event horizon>> in both
| directions
|
| Where was this proven?
| mitthrowaway2 wrote:
| The comment you're responding to didn't assert that it is
| _proven_ , but regardless: https://en.wikipedia.org/wiki/
| Hawking_radiation#Emission_pro...
| JumpCrisscross wrote:
| Hawking radiation is almost painfully constructed to
| avoid the problem of anything, even information, crossing
| back through the event horizon.
| oneshtein wrote:
| See there:
| https://news.harvard.edu/gazette/story/2022/10/black-
| hole-bu...
| JumpCrisscross wrote:
| These are ejecta from the black hole's accretion disk.
| oneshtein wrote:
| Of course, but it looks like this accretion disk was
| below the <<event horizon>>, because speed is much
| higher, 50% of speed of light, instead of typical 10%.
| JumpCrisscross wrote:
| > _it looks like this accretion disk was below the
| <<event horizon>>_
|
| No it doesn't.
|
| > _because speed is much higher, 50% of speed of light_
|
| Spin the singularity.
|
| I'd love to see a source for the authors claiming they
| believe matter exited the event horizon. That's literally
| Nobel prize groundbreaking.
| oneshtein wrote:
| > > it looks like this accretion disk was below the
| <<event horizon>>
|
| > No it doesn't.
|
| It is, because of the silence before the sudden <<burp>>.
| Something consumed all the radiation produced by the
| accretion disk. I know the only one possible solution:
| the <<event horizon>>.
|
| Astronomers says that they are not sure:
|
| > "Black holes are very extreme gravitational
| environments even before you pass that event horizon, and
| that's what's really driving this," Cendes said. "We
| don't fully understand if the material observed in radio
| waves is coming from the accretion disk or if it is being
| stored somewhere closer to the black hole. Black holes
| are definitely messy eaters, though."
|
| but I can use this as evidence that the center of black
| hole contains a dense and cold crystal. Why not?
|
| Moreover, if fractal theory is right, then we are inside
| infinite number of black holes of increasing sizes (or
| other objects). But, if we are inside a black hole, why
| sky is black and space is cold then?
| JumpCrisscross wrote:
| > _I know the only one possible solution: the <<event
| horizon>>_
|
| Try the unstable region between the ISCO and EH.
|
| > _Astronomers says that they are not sure_
|
| They're not sure where outside the EH.
|
| > _I can use this as evidence that the center of black
| hole contains a dense and cold crystal. Why not?_
|
| You're bordering on trolling, but simply, it's because
| the evidence doesn't work.
| mr_mitm wrote:
| Black holes are a prediction of general relativity. The
| same theory predicts that all properties of spacetime
| exist up until the singularity. You cannot simultaneously
| believe in black holes and some sort of discontinuation
| of spacetime before the singularity.
| uoaei wrote:
| That is a theory that makes predictions, not evidence. As
| you may note in my comments above, I am speaking
| exclusively to evidence.
| mr_mitm wrote:
| It doesn't make sense to talk about black holes outside
| the context of GR. What do you even mean by black hole if
| you can't describe it in the language of GR?
| JumpCrisscross wrote:
| > _What do you even mean by black hole if you can 't
| describe it in the language of GR?_
|
| You're right. But playing devil's advocate, there are QM
| objects that look like black holes [1] as well as
| observations of a supermassive object at Sagittarius A*.
|
| [1] https://arxiv.org/html/2307.06164v2
| uoaei wrote:
| The parts of GR we trust in order to interpret the data
| from our instruments is trusted precisely because there
| is evidence to back up _those parts of the theory_. We
| have no idea if that theory holds on the other side of a
| boundary across which no causation can occur.
| GoblinSlayer wrote:
| We don't have evidence for event horizon. Black hole is a
| hypothetical object to begin with, it exists only in
| mathematics, what evidence.
| mr_mitm wrote:
| They are singularities in the framework of general relativity,
| i.e. while ignoring quantum mechanics. I think most people
| expect the right version of quantum 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 wrote:
| 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.
| mr_mitm wrote:
| Gravity _is_ non-linear (as in: the Einstein field
| equations are non-linear differential equations).
|
| That has nothing to do with the measurement problem. Also,
| the measurement problem is only a problem of the Copenhagen
| interpretation. It doesn't exist in the many worlds
| interpretation.
| pdonis wrote:
| In the GR model of black holes, the singularity is at the _end_
| of time inside the hole, not the beginning.
| Twisol wrote:
| I think the "singularity at the beginning of time" being
| referenced here is the one postulated before / at the instant
| of the Big Bang.
| pdonis wrote:
| Ah, I see, I was parsing the sentence wrong.
| ck2 wrote:
| trying to find the PBS Space Time for that but meanwhile enjoy
|
| https://www.youtube.com/@pbsspacetime/search?query=hole
| gunian wrote:
| can confirm just delivered an amazon package in one
___________________________________________________________________
(page generated 2025-02-25 23:00 UTC)