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Is it even scientific to claim anything about black hole insides? AFAIU it's impossible by definition for any information to escape black hole insides. Any obse

Is it even scientific to claim anything about black hole insides? AFAIU it's impossible by definition for any information to escape black hole insides. Any observation or experiment is not possible. Any assumption can't be confirmed or rebuted. Basically it can't be falsified, so it's not a science according to Popper.

chungy 2y ago
We can hypothesize, but there is no known way to ever test it. At least not with the information getting out of the black hole.
- kelseyfrog 2y ago
  Without being able to test, the insides of blackholes are outside the realm of falsifiability and thus forever beyond science.
  - sliken 2y ago
    Maybe, but if we found or made a tiny black hole, something could be beyond the event horizon just before it evaporates. Or maybe spin it fast enough so the singularity is visible.
disconcision 2y ago
> AFAIU it's impossible by definition for any information to escape black hole insides. Any observation or experiment is not possible this doesnt precisely follow. observation or experiment is possible from within the event horizon, although this might limit plausible venues for publication
- jl6 2y ago
  Publish and perish.
  - sliken 2y ago
    No need to perish, current theories explain that the innermost region of a spinning black hole (all real world black holes spin) has a low gravity region where arbitrary navigation is possible. You can't escape, but you also don't have a death date with the singularity.
    - knodi123 2y ago
      Uh... But how do you get there? My understanding as a lay-person is that you can't get past the event horizon without getting spaghettified, and cooked by high-energy blue-shifted radiation.
      - sliken 2y ago
        Getting past the event horizon of a small blackhole is tough, the gravitational gradient causes spaghetification. However larger blackholes lessen the gradient at the event horizon, so it's not a problem. Not sure about the inner horizon, just saw a discussion of the paper for a spinning black hole recently, it described three distinct regions.
      - vikingerik 2y ago
        Most lay-person discussion of black holes just ignores the spaghettification and radiation problems. Those don't really have anything to do with space-time or information propagation or cosmology or such, those are just limitations of material strength and biology. The discussion is more like, if we had infinitely resilient materials or biology, what could they observe and experience.
        knodi123 2y ago
        > what could they observe and experience Observe? Nothing, once you're inside the event horizon, right? The event horizon isn't a solid wall, it's just the point at which light can only move further inward, never outward. So even inside the event horizon, we still can't observe anything further in.
      - 2y ago
- exe34 2y ago
  Cartan Null?
card_zero 2y ago
But we can have an explanation, which can be falsified by arguments, without needing to directly test the inside of black holes with instruments. > Now my reply to instrumentalism consists in showing that there are profound differences between "pure" theories and technological computation rules, and that instrumentalism can give a perfect description of these rules but is quite unable to account for the difference between them and the theories. I think that's the right quote, Popper often lets me down when I want something terse and uncomplicated.
Sakos 2y ago
This is such a weird statement. A lot of currently established science was only theorized during the early 20th century, long before we had the tools so they could be "proven" with real-world experiments. It was still science at the time.
rthnbgrredf 2y ago
We have Hawking radiation and gravitational waves and the future potential to experiment with microscopic black holes in the lab, along with the hypothesis that Planet 9 might be a primordial black hole in our solar system, there is a wealth of opportunities to explore and learn more about black holes experimentally, without entering one physically.
- santoshalper 2y ago
  Yes, but definitionally, none of those experiments can tell us anything about what is inside the black hole.
  - rthnbgrredf 2y ago
    Well, we have a pretty good understanding of how our sun works internally just by observing it from the outside, without ever digging a hole into it to observe it from the inside.
    - idiotsecant 2y ago
      That's because the sun emits a great deal of information. Black holes by definition emit none (on human time scales)
      - rthnbgrredf 2y ago
        The mentioned Hawking radiation is quite weak, weaker than we can currently measure, that's true. But for smalller black holes in the lab or for a black holes in our solar system (planet 9). It is very much possible (in the future) to detect the radiation and gain insights from it, maybe even within this century. I would direct you to the holographic principle and the AdS/CFT correspondence. Because current theory suggest that the information that falls into a black hole is not lost and can be recovered (resolving the information paradox). Similar to as we can deduce the inner workings of the sun, from the information it emits, we could be able to deduce such information from hawking radiation in case of black holes.
thriftwy 2y ago
Yes, it is scientific. For example, Kruskal–Szekeres coordinates precisely describe movement inside the black hole. https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates
csomar 2y ago
Maybe if you can create nano-blackholes and explode them later in a controlled fashion?
cjfd 2y ago
It looks like they are mostly making statements about what is happening outside the Schwarzschild radius. These are testable statements.
gigatexal 2y ago
Given our best theories we speculate what the inside of a black hole might be like. Of course we can’t know. But that’s how scientific things go: the cutting edge of human understanding is used to make predictions. Particular to the inside of a black hole, though, it’s impossible to test what we see or what happens when something passes the event horizon. I guess unless we wait basically an eternity capturing all the hawking radiation to rebuild what was sent in…
dotnet00 2y ago
From my understanding, that invokes the black hole information paradox. There should be some way in which the information of what went into a black hole is retained, a possible answer being with the Hawking radiation. We just don't know enough about black holes to say for sure that the insides can not be studied in some manner. That's kind of why a theory of quantum gravity is so relevant, without it, the inaccessibility of the inside of a black hole remains at odds with key components of quantum physics. Eg The current theory is that black holes release Hawking radiation, and studying that over the lifetime of the black hole might reveal information about the matter that went in. Understanding how this information is encoded could reveal things about the inside. Other possible explanations are that near the point of evaporation, when the black hole shrinks down to a size where quantum effects dominate, the information within becomes accessible, which could again allow potentially studying the inside.
- bongodongobob 2y ago
  Using information from Hawking Radiation to understand what went in: while it might be possible, isn't this on the same practical level of unscrambling an egg? Sure we could do it with nanobots but is that really a possibility or just a mathematical curiosity?
  - dotnet00 2y ago
    Given the amount of mass typically involved, probably just a mathematical curiosity, but if that's the only way we can figure out to try to understand the inside, maybe we'll eventually be able to generate microblackholes from tiny amounts of matter, collect the hawking radiation and study those in this manner (they'd evaporate pretty quickly). Edit: I forgot to add in my original post that there's also just the possibility that the mechanism by which this paradox is resolved still hides the inside.
- deleted 2y ago
  [deleted]

chungy 2y ago

We can hypothesize, but there is no known way to ever test it. At least not with the information getting out of the black hole.

kelseyfrog 2y ago
Without being able to test, the insides of blackholes are outside the realm of falsifiability and thus forever beyond science.
- sliken 2y ago
  Maybe, but if we found or made a tiny black hole, something could be beyond the event horizon just before it evaporates. Or maybe spin it fast enough so the singularity is visible.

disconcision 2y ago

> AFAIU it's impossible by definition for any information to escape black hole insides. Any observation or experiment is not possible this doesnt precisely follow. observation or experiment is possible from within the event horizon, although this might limit plausible venues for publication

jl6 2y ago
Publish and perish.
- sliken 2y ago
  No need to perish, current theories explain that the innermost region of a spinning black hole (all real world black holes spin) has a low gravity region where arbitrary navigation is possible. You can't escape, but you also don't have a death date with the singularity.
  - knodi123 2y ago
    Uh... But how do you get there? My understanding as a lay-person is that you can't get past the event horizon without getting spaghettified, and cooked by high-energy blue-shifted radiation.
    - sliken 2y ago
      Getting past the event horizon of a small blackhole is tough, the gravitational gradient causes spaghetification. However larger blackholes lessen the gradient at the event horizon, so it's not a problem. Not sure about the inner horizon, just saw a discussion of the paper for a spinning black hole recently, it described three distinct regions.
    - vikingerik 2y ago
      Most lay-person discussion of black holes just ignores the spaghettification and radiation problems. Those don't really have anything to do with space-time or information propagation or cosmology or such, those are just limitations of material strength and biology. The discussion is more like, if we had infinitely resilient materials or biology, what could they observe and experience.
      - knodi123 2y ago
        > what could they observe and experience Observe? Nothing, once you're inside the event horizon, right? The event horizon isn't a solid wall, it's just the point at which light can only move further inward, never outward. So even inside the event horizon, we still can't observe anything further in.
    - 2y ago
exe34 2y ago
Cartan Null?

card_zero 2y ago

But we can have an explanation, which can be falsified by arguments, without needing to directly test the inside of black holes with instruments. > Now my reply to instrumentalism consists in showing that there are profound differences between "pure" theories and technological computation rules, and that instrumentalism can give a perfect description of these rules but is quite unable to account for the difference between them and the theories. I think that's the right quote, Popper often lets me down when I want something terse and uncomplicated.

Sakos 2y ago

This is such a weird statement. A lot of currently established science was only theorized during the early 20th century, long before we had the tools so they could be "proven" with real-world experiments. It was still science at the time.

rthnbgrredf 2y ago

We have Hawking radiation and gravitational waves and the future potential to experiment with microscopic black holes in the lab, along with the hypothesis that Planet 9 might be a primordial black hole in our solar system, there is a wealth of opportunities to explore and learn more about black holes experimentally, without entering one physically.

santoshalper 2y ago
Yes, but definitionally, none of those experiments can tell us anything about what is inside the black hole.
- rthnbgrredf 2y ago
  Well, we have a pretty good understanding of how our sun works internally just by observing it from the outside, without ever digging a hole into it to observe it from the inside.
  - idiotsecant 2y ago
    That's because the sun emits a great deal of information. Black holes by definition emit none (on human time scales)
    - rthnbgrredf 2y ago
      The mentioned Hawking radiation is quite weak, weaker than we can currently measure, that's true. But for smalller black holes in the lab or for a black holes in our solar system (planet 9). It is very much possible (in the future) to detect the radiation and gain insights from it, maybe even within this century. I would direct you to the holographic principle and the AdS/CFT correspondence. Because current theory suggest that the information that falls into a black hole is not lost and can be recovered (resolving the information paradox). Similar to as we can deduce the inner workings of the sun, from the information it emits, we could be able to deduce such information from hawking radiation in case of black holes.

thriftwy 2y ago

Yes, it is scientific. For example, Kruskal–Szekeres coordinates precisely describe movement inside the black hole. https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates

csomar 2y ago

Maybe if you can create nano-blackholes and explode them later in a controlled fashion?

cjfd 2y ago

It looks like they are mostly making statements about what is happening outside the Schwarzschild radius. These are testable statements.

gigatexal 2y ago

Given our best theories we speculate what the inside of a black hole might be like. Of course we can’t know. But that’s how scientific things go: the cutting edge of human understanding is used to make predictions. Particular to the inside of a black hole, though, it’s impossible to test what we see or what happens when something passes the event horizon. I guess unless we wait basically an eternity capturing all the hawking radiation to rebuild what was sent in…

dotnet00 2y ago

From my understanding, that invokes the black hole information paradox. There should be some way in which the information of what went into a black hole is retained, a possible answer being with the Hawking radiation. We just don't know enough about black holes to say for sure that the insides can not be studied in some manner. That's kind of why a theory of quantum gravity is so relevant, without it, the inaccessibility of the inside of a black hole remains at odds with key components of quantum physics. Eg The current theory is that black holes release Hawking radiation, and studying that over the lifetime of the black hole might reveal information about the matter that went in. Understanding how this information is encoded could reveal things about the inside. Other possible explanations are that near the point of evaporation, when the black hole shrinks down to a size where quantum effects dominate, the information within becomes accessible, which could again allow potentially studying the inside.

bongodongobob 2y ago
Using information from Hawking Radiation to understand what went in: while it might be possible, isn't this on the same practical level of unscrambling an egg? Sure we could do it with nanobots but is that really a possibility or just a mathematical curiosity?
- dotnet00 2y ago
  Given the amount of mass typically involved, probably just a mathematical curiosity, but if that's the only way we can figure out to try to understand the inside, maybe we'll eventually be able to generate microblackholes from tiny amounts of matter, collect the hawking radiation and study those in this manner (they'd evaporate pretty quickly). Edit: I forgot to add in my original post that there's also just the possibility that the mechanism by which this paradox is resolved still hides the inside.
deleted 2y ago
[deleted]