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Dead Stars Don’t Radiate

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Re: Dead Stars Don’t Radiate

#31

Post by pixl97 »

jodrellblank wrote: post #26
jiggawatts wrote: post #22

Earlier quoted context omitted.

> The conservation of baryon number is not consistent with the physics of black hole evaporation via Hawking radiation. There are other black hole models that can conserve these quantum numbers! Speaking of things that are so obviously true that you must be an idiot not to agree, there are statements so obviously false that you have to be an idiot to agree: People keep repeating the nonsense put out by Penrose, which…

> " To maintain consistency with outside observers, this evaporation must occur fast enough that the victim can never reach any surface. Instead, the black hole recedes from them, evaporating faster and faster. " If this is radiating a star's mass worth Hawking radiation particles, is it like the Solar Wind, and if it's happening ever faster is there a point where it would start pushing the victim away from the black…

I don't think the hawking radiation occurs at the edge of the event horizon itself.

Arvin Ash just did a video on this

https://www.youtube.com/watch?v=UxVssUb0MsA

It appears to occur outside the event horizon in a large area.

Re: Dead Stars Don’t Radiate

#32

Post by BlueTemplar »

> As Mark Twain said, “A lie can travel around the world and back again while the truth is lacing up its boots.” Actually he probably didn’t say that—but everyone keeps saying he did, illustrating the point perfectly.

It was Gandalf who said that of course. And before you try to contradict me, let me point out that Gandalf is a wizard that has no need to bother with silly things like spacetime continuity.

P.S.: https://quoteinvestigator.com/2014/07/13/truth/

> In conclusion, there exists a family of expressions contrasting the dissemination of lies and truths, and these adages have been evolving for more than 300 years. Jonathan Swift can properly be credited with the statement he wrote in 1710 [(that does not mention footwear yet)].

Re: Dead Stars Don’t Radiate

#33

Post by pixl97 »

gruturo wrote: post #19
EA-3167 wrote: post #8

Earlier quoted context omitted.

You have to remember the "one particle in the pair fails to escape the event horizon" explanation is a simplification of the alleged reality, which is the scattering of particles (or fields) in the presence of an event horizon. As far as I know there is no intuitive, non-mathematical way to describe this accurately, so science communicators of all stripes tend to approximate it in ways that can mislead the audience.…

Thanks! I just learned something!

Arvin Ash just did an episode on exactly this effect. The modern way we understand it is much to simplified.

https://www.youtube.com/watch?v=UxVssUb0MsA

Re: Dead Stars Don’t Radiate

#34

Post by kmm »

nimish wrote: post #4

There's an issue this highlights and it's not that the original authors were stupid so much as there's clearly a lot of knowledge held in silos. That's not a good thing if your goal is to advance everyone's knowledge. Whatever is going on in academia is failing relatively closely related fields which is not good.

Is it really that siloed? The condition mentioned in the article (there being a global timelike Killing field) is discussed in all introductory texts on quantum field theory in curved spaces, it's even present in the first few paragraphs of the relevant Wikipedia article[1]. Even if it doesn't apply here, the authors ought to have mentioned why not.

I don't think they were stupid per se, nor malicious, but perhaps cavalier in pushing a result with such unexpected consequences without getting a consult.

1: https://en.wikipedia.org/wiki/Quantum_field_theory_in_curved...

Re: Dead Stars Don’t Radiate

#35

Post by nabla9 »

quantadev wrote: post #16

In black holes we have essentially a "loss of a dimension" (it's a much bigger story to explain what that even means, that I won't attempt here), so it might be the case that the three-quark arrangement known as 'baryons' only forms according to number of space dimensions (3D == 3 Quarks), making baryons only happen in 3D, so that when stuff reaches an event horizon, the quarks rip apart and rearrange into something…

> I'm someone who thinks the 'surface' of an event horizon is where the laws are preserved,

I don't think this is a good way to think it. If black hole is big enough, there is nothing strange happening in the event horizon, no significant length contraction, nothing.

Re: Dead Stars Don’t Radiate

#36

Post by quantadev »

BlueTemplar wrote: post #29
quantadev wrote: post #16

In black holes we have essentially a "loss of a dimension" (it's a much bigger story to explain what that even means, that I won't attempt here), so it might be the case that the three-quark arrangement known as 'baryons' only forms according to number of space dimensions (3D == 3 Quarks), making baryons only happen in 3D, so that when stuff reaches an event horizon, the quarks rip apart and rearrange into something…

> I'm someone who thinks the 'surface' of an event horizon is where the laws are preserved, and that the singularity or even perhaps the entire interior inside black holes may simply not exist at all. Sounds tempting, but then what happens at the transition : when a sphere of matter gets just a little bit too dense ?

It's just like the Lorentz Tranform or any other of the laws of Relativity. Things can get very massive and/or time can slow way down, but ultimately there's not a "problem" (i.e. mathematical failure requiring the theory to be extended) until the speed of light is reached, as an asymptotic limit.

But you're raising a good point that maybe Lorentz is pointing to 'non-integer dimensionality' where even enough mass crammed into a small enough space causes the "new maths" to begin to noticeably take hold. Like I said I see Lorentz as a way to transform dimensionality from N-D to (N +/- 1)D, but in a continuous and 'differentiable' way.

In super simplistic terms Lorentz is a "compression" function where one dimension of space is compressed perfectly flat, which is the mathematical equivalent of removing that dimension from the 'degrees of freedom' of the system.

Re: Dead Stars Don’t Radiate

#37

Post by quantadev »

nabla9 wrote: post #35
quantadev wrote: post #16

In black holes we have essentially a "loss of a dimension" (it's a much bigger story to explain what that even means, that I won't attempt here), so it might be the case that the three-quark arrangement known as 'baryons' only forms according to number of space dimensions (3D == 3 Quarks), making baryons only happen in 3D, so that when stuff reaches an event horizon, the quarks rip apart and rearrange into something…

> I'm someone who thinks the 'surface' of an event horizon is where the laws are preserved, I don't think this is a good way to think it. If black hole is big enough, there is nothing strange happening in the event horizon, no significant length contraction, nothing.

Some "infinities" of singularity are at the center sure, but all the maximal Relativistic effects are at the EH surface. It's even proven that the entropy (informational content roughly) is equal to the EH area divided by the number of planc-length square areas, as the amount of quantum arrangements of information that are allowed "inside". That is a HUGE hint everything's remaining on the surface.

For example, when you see a clock fall into a BH you see it stop ticking at the EH, not at the center. It's a common misconception that everything about them is at the center, but everything interesting is at the surface.

Re: Dead Stars Don’t Radiate

#38

Post by lupire »

tekla wrote: post #12
nimish wrote: post #4

There's an issue this highlights and it's not that the original authors were stupid so much as there's clearly a lot of knowledge held in silos. That's not a good thing if your goal is to advance everyone's knowledge. Whatever is going on in academia is failing relatively closely related fields which is not good.

99.999999999% of people do not have enough knowledge to even dream of beginning to understand a majority of research. Adults can barely read, much less be able to pass Calc 1.

Wher are you hiding 92 Billion people?

Re: Dead Stars Don’t Radiate

#39

Post by mlhpdx »

> As Mark Twain said, “A lie can travel around the world and back again while the truth is lacing up its boots.” Actually he probably didn’t say that—but everyone keeps saying he did, illustrating the point perfectly.

Well played.

Re: Dead Stars Don’t Radiate

#40

Post by jhalstead »

moefh wrote: post #18
nimish wrote: post #4

There's an issue this highlights and it's not that the original authors were stupid so much as there's clearly a lot of knowledge held in silos. That's not a good thing if your goal is to advance everyone's knowledge. Whatever is going on in academia is failing relatively closely related fields which is not good.

> There's an issue this highlights [...] there's clearly a lot of knowledge held in silos. I think the real issue this highlights -- which is something everyone knows and still everyone does -- is that people love to spread and discuss sensational stories, and no one likes to hear naysayers ruining the fun. Look the discussion of the original story here in HN[1]. There's a comment by A_D_E_P_T way down in the discuss…

Direct link to A_D_E_P_T's comment: https://news.ycombinator.com/item?id=43964524
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