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Do Black Holes really exist?

Anonymous Mon 25 May 22:44:59 2020 No.11711563 View Reply Original Report

Quoted By: >>11712220 >>11712528 >>11712720 >>11713022 >>11713055 >>11713248 >>11713337

We know at least 2 things about black holes.
1) They evaporate in a finite time relative to an external observer via Hawking Radiation
2) There's infinite time dilation between in-falling matter near the event horizon and an external observer that is some finite distance away from the event horizon.

This means that the black hole will evaporate before any matter reaches the event horizon.

Anonymous

Anonymous Mon 25 May 2020 23:06:58 No.11711618 Report

Quoted By:

Any /physics/ fags can explain how both 1) and 2) can hold?

Anonymous

Anonymous Tue 26 May 2020 02:52:12 No.11712220 Report

Quoted By:

>>11711563
The black hole can indeed start radiating before matter reaches the event horizon. When it became a black hole, it already had nonzero mass, so indeed it can radiate. What's the problem?

Anonymous

Anonymous Tue 26 May 2020 05:10:31 No.11712528 Report

Quoted By: >>11712544 >>11712945

>>11711563
>Any information that goes past the singularity is gone and can never be reclaimed from the black hole
>The black hole eventually evaporates as all of its mass is radiated away from Hawking Radiation
How can both of these be true? The information that goes past the singularity has to leave if the black hole evaporates.

Anonymous

Anonymous Tue 26 May 2020 05:25:40 No.11712544 Report

Quoted By: >>11712580

>>11712528
https://en.wikipedia.org/wiki/Thorne%E2%80%93Hawking%E2%80%93Preskill_bet

Anonymous

Anonymous Tue 26 May 2020 05:46:12 No.11712580 Report

Quoted By: >>11712586

>>11712544
Your article links to two guys arguing over whether or not the information that goes past the singularity leaves the black hole as radiation, with neither of them being able to come to an agreement.

So again I pose the questions:
>Any information that goes past the singularity is gone and can never be reclaimed from the black hole
>The black hole eventually evaporates as all of its mass is radiated away from Hawking Radiation
How can both of these be true?

Anonymous

Anonymous Tue 26 May 2020 05:51:23 No.11712586 Report

Quoted By: >>11712614

>>11712580
>Hawking announced that he was conceding the bet, and that he now believed that black hole horizons should fluctuate and leak information

the debate is whether or not the radiation leaving a black hole contains the information that entered it or whether it is new information, with the consensus being that it is the information that entered. thus your first point would be wrong.
however this is clearly not a well-established point and likely to be debated still

Anonymous

Anonymous Tue 26 May 2020 06:05:33 No.11712614 Report

Quoted By: >>11712635

>>11712586
It has to be the information that entered. Otherwise there needs to be an explanation on what happened to all the shit that entered by the time the black hole is evaporated.
>It just goes in to another universe bro
Shit like this is why science is starting to be seen as another form of religion.

Anonymous

Anonymous Tue 26 May 2020 06:11:39 No.11712635 Report

Quoted By: >>11712640

>>11712614
I'm glad that you can come up with a one-line answer to a thought experiment that some of the best physicists struggled with. where are you going to publish your proof of this?
>Otherwise there needs to be an explanation on what happened to all the shit that entered by the time the black hole is evaporated
exactly. but even if we don't have an explanation for where it goes, we don't necessarily know that this is false. it hasn't been disproven.

Anonymous

Anonymous Tue 26 May 2020 06:15:45 No.11712640 Report

Quoted By: >>11712661

>>11712635
They struggle because they refuse to accept that they are ever wrong. The moment they are wrong that fabricate a new theory out of their ass that can't be proven and therefore absolves them from admitting they are wrong.
>It's just dark matter bro

Anonymous

Anonymous Tue 26 May 2020 06:24:25 No.11712661 Report

Quoted By:

>>11712640
why are you on this board if you have such a disdain for science?
just because we don't fully understand something doesn't mean it's a trivial problem that you can solve "just by thinking about it lulz"

Anonymous

Anonymous Tue 26 May 2020 06:48:24 No.11712700 Report

Quoted By: >>11713050 >>11713387

Let's say you are one grain of rice away from forming a black hole. The mass is there, very compact, probably something like a neutron star. Then we drop the rice grain, boom, we have a black hole. Then we wait for the black hole to loose an equivalent of a rice grain of mass through HR. What do we have then? Is it still a black hole?

Anonymous

Anonymous Tue 26 May 2020 07:01:19 No.11712720 Report

Quoted By: >>11713022 >>11713517

>>11711563
the craps already fallen into the hole, the information via photons or whatever that it did just takes literally forever to get to you

Anonymous

Anonymous Tue 26 May 2020 09:07:35 No.11712945 Report

Quoted By:

>>11712528
what is information?
As far as I know, maintaining symmetry is all the requirements of physical processes.

Anonymous

Anonymous Tue 26 May 2020 09:50:31 No.11713022 Report

Quoted By: >>11713517

>>11711563
its a cop out but basically space and time flip

>>11712720
essentially this

t.not a physicist

Anonymous

Anonymous Tue 26 May 2020 10:02:54 No.11713043 Report

Quoted By:

I'll show you a black hole, anon

Anonymous

Anonymous Tue 26 May 2020 10:06:02 No.11713050 Report

Quoted By:

>>11712700
Yes, it would probably collapse into a black hole by itself given enough time

Anonymous

Anonymous Tue 26 May 2020 10:07:15 No.11713055 Report

Quoted By:

>>11711563
>This means that the black hole will evaporate before any matter reaches the event horizon.
Yes, most of the black hole mass is probably on the surface

Anonymous

Anonymous Tue 26 May 2020 11:20:42 No.11713181 Report

Quoted By: >>11713387

Holographic principle states that all of information contained in infalling matter is encoded at the event horizon.
So there's that and supposedly also the mass is all in the center singularity. Yet by evaporating the mass has to get out somehow. I don't know how this works.

Anonymous

Anonymous Tue 26 May 2020 11:54:38 No.11713248 Report

Quoted By: >>11713280

>>11711563
we know fuck all about BH.
It's at best an hypothesis, speculation at worst.

Anonymous

Anonymous Tue 26 May 2020 12:05:49 No.11713280 Report

Quoted By: >>11713304 >>11713325

>>11713248
>we
you mean “I”, right?

Anonymous

Anonymous Tue 26 May 2020 12:15:26 No.11713304 Report

Quoted By:

>>11713280
hell no I'm not black, shut up stupid motherfucker

Anonymous

Anonymous Tue 26 May 2020 12:22:58 No.11713325 Report

Quoted By: >>11713400

>>11713280
Show me some first-hand data about matter evaporating due to Hawking Radiation, or about in-falling matter in the close vicinity of a bh event horizon.

Anonymous

Anonymous Tue 26 May 2020 12:27:08 No.11713337 Report

Quoted By:

>>11711563
Matter passes the event horizon just fine, it's a nonphysical singularity.

Anonymous

Anonymous Tue 26 May 2020 12:45:56 No.11713387 Report

Quoted By: >>11713479

>>11713181
The mass doesn't get out, negative energy anti particle goes in

>>11712700
Yes it will keep being a black hole. An analogue could be building a building higher and higher. At some point the load gets too high, the deepest floors collapse and the entire thing comes crashing down. Even after you clear some of the rubble trough hawking radiation the rest will still be rubble. You can also bypass the process by taking a small pile of building materials and then adding say TNT to artificially create the rubble.

Anonymous

Anonymous Tue 26 May 2020 12:49:45 No.11713400 Report

Quoted By: >>11713410

>>11713325
define first hand data
obviously you can’t fly to a black hole and gather a handful of radiation.
regions with very strong gravitational attraction, like quasars emit continuous low IR radiation, corresponding to a blackbody temperature expected from theory.

Anonymous

Anonymous Tue 26 May 2020 12:49:51 No.11713401 Report

Quoted By:

$\displaystyle \begin{align*} \text{Mass} && M \\ \text{Radius} && R &= M \cdot \frac{2G}{c^2} \\ \text{Surface area} && A &= M^2 \cdot \frac{16 \pi G^2}{c^4} \\ \text{Surface gravity} && \kappa &= \frac{1}{M} \cdot \frac{c^4}{4G} \\ \text{Surface tides} && d \kappa_R &= \frac{1}{M^2} \cdot \frac{c^6}{4G^2} \\ \text{Entropy} && S &= M^2 \cdot \frac{4 \pi G }{ \hbar c \; ln10} \\ \text{Temperature} && T &= \frac{1}{M} \cdot \frac{ \hbar c^3 }{8k \pi G} \\ \text{Luminosity} && L &= \frac{1}{M^2} \cdot \frac{ \hbar c^6}{15360 \pi G^2} \\ \text{Lifetime} && t &= M^3 \cdot \frac{5120 \pi G^2}{ \hbar c^4} \\ \end{align*} $

G https://en.wikipedia.org/wiki/Gravitational_constant
c https://en.wikipedia.org/wiki/Speed_of_light
? https://en.wikipedia.org/wiki/Planck_constant#Value
k https://en.wikipedia.org/wiki/Boltzmann_constant

Anonymous

Anonymous Tue 26 May 2020 12:53:47 No.11713410 Report

Quoted By:

>>11713400
nvm, just saw that the radiation is too faint to distinguish from noise/cmb.

Anonymous

Anonymous Tue 26 May 2020 13:35:26 No.11713479 Report

Quoted By: >>11713493

>>11713387
>The mass doesn't get out
Then where does it go? Black holes lose mass and can theoretically evaporate to 0.

Anonymous

Anonymous Tue 26 May 2020 13:40:42 No.11713493 Report

Quoted By:

>>11713479
Are you blind or dumb

Anonymous

Anonymous Tue 26 May 2020 13:56:15 No.11713517 Report

Quoted By: >>11713522 >>11713525

>>11712720
>>11713022
>the craps already fallen into the hole, the information via photons or whatever that it did just takes literally forever to get to you
Time moves slower on a satellite orbiting the earth than one on the surface.

If an alien civilisation launched a satellite with a clock into Earth's orbit 4 billion years ago, the satellite's clock would be 36 hours ahead of the one on the surface. We can compare the two clocks later.

The same principle should apply near the surface of a black hole. Time is moving slower there. The relative time dilation between an external observer and the in-falling matter approaches infinity as the in-falling matter gets closer to the event horizon.

If the black hole is hypothesised to evaporate (due to Hawking radiation) in a finite time relative to an external observer that is some distance away from a black hole, then how can the in-falling matter reach the event horizon before it evaporates?

Again correct me if I've made a mistake here.

t. not a physicist either

Anonymous

Anonymous Tue 26 May 2020 13:58:06 No.11713522 Report

Quoted By:

>>11713517
>t. not a physicist either
I do have a math background so feel free to show any GR equations.

Anonymous

Anonymous Tue 26 May 2020 13:59:28 No.11713525 Report

Quoted By:

>>11713517
>Time moves slower on a satellite orbiting the earth than one on the surface.
Sorry this is reversed.

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