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First proof that "plunging regions" exist around black holes in space

ox.ac.uk

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Re: First proof that "plunging regions" exist around black holes in space

#51

Post by evo »

sliken wrote: post #22
ganzuul wrote: post #11

Why is it that some experts say stuff falls into the center of a black hole while others say it slows down and never passes the event horizon? Is it just semantics?

From the external view you never enter, just get dimmer as you approach the speed of light and the time dilation keeps increasing. From the viewpoint of the one falling in, you just fall in and cross the horizon without noticing. Does make you wonder if time dilation gets so extreme, could another black hole wonder by, offset the gravity of the black hole, and let you escape. Even if it takes a billion years.

I suspect that would fall under the rule that if two black holes’ respective event horizons ever cross, they merge and initiate the eventual merger of the two respective black holes.

Re: First proof that "plunging regions" exist around black holes in space

#52

Post by Filligree »

sliken wrote: post #22
ganzuul wrote: post #11

Why is it that some experts say stuff falls into the center of a black hole while others say it slows down and never passes the event horizon? Is it just semantics?

From the external view you never enter, just get dimmer as you approach the speed of light and the time dilation keeps increasing. From the viewpoint of the one falling in, you just fall in and cross the horizon without noticing. Does make you wonder if time dilation gets so extreme, could another black hole wonder by, offset the gravity of the black hole, and let you escape. Even if it takes a billion years.

The time dilation does not act in that way. You will not experience the outside universe speeding up, at least not by very much; the reason for this “paradox” is primarily that photons coming off you take longer and longer to climb out, and the ones from right when you crossed the event horizon never will.

Re: First proof that "plunging regions" exist around black holes in space

#53

Post by santoshalper »

rthnbgrredf wrote: post #26
vbezhenar wrote: post #5

Earlier quoted context omitted.

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.

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.

Yes, but definitionally, none of those experiments can tell us anything about what is inside the black hole.

Re: First proof that "plunging regions" exist around black holes in space

#54

Post by klyrs »

MeImCounting wrote: post #48
klyrs wrote: post #46

Earlier quoted context omitted.

Don't get me wrong, I love reading and watching sci-fi! And actually, that's a great source of inspiration to keep my mind sharp; a superintelligence unleashed on our world today, with pathetically insecure networked listening devices in all of our pockets, a populace demonstrably manipulable through social media, etc; humanity has nothing but literal prayer to protect itself from actual superintelligence. Which isn'…

At the risk of repeating myself, yes the LLM hype is quite overdone and annoying. What you say is true people have bought into a fantasy which is wholly unrealistic. Unfortunately your view is altogether tiresome and much harder to scroll past than the juvenile LLM excitement because it could actually do some real harm in the long term. No 'The Terminator" was not a documentary, nor was "The Matrix" nor even is your…

I was cured of blind techno-optimism years ago. The race for superintelligence is between ad-slinging megacorps and authoritarian governments. Whoever wins, we humans lose.

Re: First proof that "plunging regions" exist around black holes in space

#55

Post by dotnet00 »

vbezhenar wrote: post #5
gigatexal wrote: post #2

Still continues to amaze me that the more they look the more they confirm Einstein. Yet we know — or strongly suspect — that at the singularity and within the BH general relativity breaks down. I hope we see a unification of GR and Quantum mechanics in my lifetime. Would be really neat

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.

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.

Re: First proof that "plunging regions" exist around black holes in space

#56

Post by jameshart »

U1F984 wrote: post #43
sliken wrote: post #21

Earlier quoted context omitted.

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.

I can't find anything about these low gravity regions (Google redirects me to your post) but they sound interesting. Can you share some reading material?

The entry point is probably looking at how Penrose Diagrams describe black holes.

Recent Veritasium video: https://www.youtube.com/watch?v=6akmv1bsz1M

Wiki: https://en.wikipedia.org/wiki/Penrose_diagram

Re: First proof that "plunging regions" exist around black holes in space

#57

Post by MeImCounting »

klyrs wrote: post #54
MeImCounting wrote: post #48

Earlier quoted context omitted.

At the risk of repeating myself, yes the LLM hype is quite overdone and annoying. What you say is true people have bought into a fantasy which is wholly unrealistic. Unfortunately your view is altogether tiresome and much harder to scroll past than the juvenile LLM excitement because it could actually do some real harm in the long term. No 'The Terminator" was not a documentary, nor was "The Matrix" nor even is your…

I was cured of blind techno-optimism years ago. The race for superintelligence is between ad-slinging megacorps and authoritarian governments. Whoever wins, we humans lose.

I Feel like were having two different conversations here. Who said anything about optimism? Are those the two options now optimism or doomerism? No space left for anything approaching realism?

I criticize blind techno-doomerism for its use of clanky old worn out cliches from the sci-fi of last century. I criticize LLM bros for being naive and blinded by advertising. Both groups completely misunderstood the relevant sci-fi from this century, if they actually bothered to read any.

Sometimes between the rabid hype-bros and the holier-than-thou doomers you can find actual conversation about the nature of human interaction with theoretical future machine intelligence, how LLMs relate to that and the technical aspects of creating such a thing. Its rare but it is out there.

Re: First proof that "plunging regions" exist around black holes in space

#58

Post by vikingerik »

knodi123 wrote: post #31
sliken wrote: post #21

Earlier quoted context omitted.

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.

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.

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.

Re: First proof that "plunging regions" exist around black holes in space

#59

Post by db48x »

knodi123 wrote: post #31
sliken wrote: post #21

Earlier quoted context omitted.

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.

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.

“Spaghettification” only happens to large enough objects near small enough gravitational sources. If the Moon got too close to the Earth, closer than the Roche Limit, then it would break up into a ring of debris. But a communications satellite can exist at that same distance with no ill effects.

The same is true for black holes. A rocket or a human diving into a stellar mass non–spinning black hole would be “spaghettified”; they would be broken up into a thin stream of debris as they crossed the Roche Limit before they crossed the event horizon. But they could cross the event horizon of a much larger black hole, such as a supermassive black hole at the center of a galaxy.

In fact, if the black hole were massive enough then the gravitational field near the event horizon would be so mild as to be Earth–like. If you were to stuff all of the mass of three or four Milky Way–type galaxies into one black hole, you could build an actively–stabilized structure around the black hole to create a livable environment of truly insane proportions with Earth–normal gravity. Look up Birch Worlds sometime.

Re: First proof that "plunging regions" exist around black holes in space

#60

Post by SiempreViernes »

legohead wrote: post #10

And the graphic on the page is the opposite of what they are describing...

No, the inner most stable orbit is just not very large which the graphics illustrate by the central black region around the black hole.
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