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Black Hole Energy Distribution

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We know that the sphere inside the black hole itself is almost at absolute zero Kelvin. Totally cold.

We also know that matter absorbed by the black hole is distributed equally on its surface. And we know it emits Hawking radiation when that happens.

The theory is also that the temperature just beyond the event horizon (as I've understood it) is millions of degrees hot. But can we be sure of that?

How do we know that there is heat around the hole? Could it not be that all the energy absorbed, escapes as Hawking radiation?

(Sorry for any factual mistakes. I'm not a pro.)

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8 minutes ago, QuantumT said:

We know that the sphere inside the black hole itself is almost at absolute zero Kelvin. 

Do we?

8 minutes ago, QuantumT said:

We also know that matter absorbed by the black hole is distributed equally on its surface. 

Really?

Can you provide references for the above?

We cannot know anything about the inside of a black hole. 

9 minutes ago, QuantumT said:

The theory is also that the temperature just beyond the event horizon (as I've understood it) is millions of degrees hot. But can we be sure of that?

This sounds like the “firewall hypothesis” a result from attempting to apply quantum theory to black holes. But I’m not sure anyone thinks it represents reality; it is a problem to be solved. 

 

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1 minute ago, Strange said:

Do we?

Really?

Can you provide references for the above?

We cannot know anything about the inside of a black hole. 

This sounds like the “firewall hypothesis” a result from attempting to apply quantum theory to black holes. But I’m not sure anyone thinks it represents reality; it is a problem to be solved. 

As I said, but you so elegantly ignored:

15 minutes ago, QuantumT said:

Sorry for any factual mistakes. I'm not a pro.

 

 

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27 minutes ago, QuantumT said:

(Sorry for any factual mistakes. I'm not a pro.)

You don't need to be a pro to know  what the 'facts' are.

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1 minute ago, Itoero said:

You don't need to be a pro to know  what the 'facts' are.

I've learned that small black holes are warm, and big ones are cold. And the big ones are the most intriguing.

But what I would like to learn is what happens to the heat. Is it wrong to assume that it escapes with Hawking radiation? If so, why?

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15 hours ago, QuantumT said:

As I said, but you so elegantly ignored:

Don't you want your mistakes corrected? How was Strange supposed to respond? He just wanted to know where you got your misconceptions. He ignored nothing.

 

We CAN'T know anything for certain about the inside of a black hole because the geometry of spacetime is too highly curved around such hot, dense matter. Hawking radiation is all on our side of the event horizon. Nothing escapes once past it, since the insanely curved spacetime inside allows only one inevitable path to the degenerate matter. In essence, since no amount of energy can possibly change your direction, whatever is at the heart inevitably becomes your future.

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Posted (edited)
15 hours ago, QuantumT said:

I've learned that small black holes are warm, and big ones are cold. And the big ones are the most intriguing.

But what I would like to learn is what happens to the heat. Is it wrong to assume that it escapes with Hawking radiation? If so, why?

I don't think you can make valid assumptions concerning the temperature.

I once read a paper (think of S Hawking) that stated it wasn't a real event horizon but an apparent horizon.https://arxiv.org/pdf/1601.00921.pdf

I didn't read this paper but this also suggests there is no event horizon. https://arxiv.org/abs/1710.09299

Edited by Itoero

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15 hours ago, QuantumT said:

As I said, but you so elegantly ignored:

Which is why I asked where you got that info. It looks like the source was mistaken (or maybe just confusing).

15 hours ago, QuantumT said:

I've learned that small black holes are warm, and big ones are cold. And the big ones are the most intriguing.

But what I would like to learn is what happens to the heat. Is it wrong to assume that it escapes with Hawking radiation? If so, why?

As black holes lose energy (and therefore mass) through Hawking radiation, they get smaller. The temperature is inversely proportional to the mass, so it goes up as the black hole shrinks. (Which means that the black hole shrinks even faster.)

But this is only significant for very small black holes. Any realistic black hole is going to gain mass faster than it can radiate it away.

 

15 minutes ago, Itoero said:

I don't think you can make valid assumptions concerning the temperature.

It is not an assumption, it is a calculation based on an approximation of QM in curved space.

16 minutes ago, Itoero said:

I once read a paper (think of S Hawking) that stated it wasn't a real event horizon.

There is still a lot of theoretical work going on regarding black holes, in particular concerning possible quantum effects (which is where Hawking radiation comes from). One hypothesis is that the event horizon could be porous, when quantum effects are taken into account.

There are a few models where black holes or event horizons don't form at all, but they are generally pretty speculative.

The black hole "firewall" (where an observer falling into a black hole would see an extremely high temperature flux of particles at the event horizon) is another consequence of trying to apply quantum theory. Most people assume that this just indicates our lack of understanding of the physics of black holes.

21 minutes ago, Itoero said:

I didn't read this paper but this also suggests there is no event horizon. https://arxiv.org/abs/1710.09299

That seems to be about theoretical analogs of black holes in a particular type of two dimensional fluid. Other fluid models of black holes have demonstrated the existence of the equivalents of event horizons and even Hawking radiation

For example: https://www.nature.com/news/hawking-radiation-mimicked-in-the-lab-1.16131.

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1 hour ago, QuantumT said:

Sorry for the delayed response!

I got it from Fraser Cain (Universe Today):

https://phys.org/news/2016-09-cold-black-holes.html

OK. But that does not say that "the sphere inside the black hole itself is almost at absolute zero Kelvin" or that "matter absorbed by the black hole is distributed equally on its surface".

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3 minutes ago, Strange said:

OK. But that does not say that "the sphere inside the black hole itself is almost at absolute zero Kelvin" or that "matter absorbed by the black hole is distributed equally on its surface".

Look again. It says "close to 0 kelvin" in big black holes.

The matter distribution on the surface might not have been mentioned in that article, but it is a commonly known theory, as far as I know.

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3 minutes ago, QuantumT said:

Look again. It says "close to 0 kelvin" in big black holes.

It says: "We're talking about the temperature of the black hole's event horizon" So not inside the black hole.

3 minutes ago, QuantumT said:

The matter distribution on the surface might not have been mentioned in that article, but it is a commonly known theory, as far as I know.

I have never heard of it.

Anything falling into a black hole will pass the event horizon at the speed of light and quickly reach the centre of the black hole.

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2 minutes ago, Strange said:

It says: "We're talking about the temperature of the black hole's event horizon" So not inside the black hole.

Further down it says

Quote

The most massive black holes in the Universe, the supermassive black holes with millions of times the math of the Sun will have a temperature of 1.4 x 10-14 Kelvin. That's low. Almost absolute zero, but not quite.

3 minutes ago, Strange said:

I have never heard of it.

I'll try to find it when I have time.

 

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Just now, QuantumT said:

Further down it says

But it is still talking about the temperature at the event horizon.

 

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3 hours ago, Strange said:

I have never heard of it.

I think it's a part of Susskind's Holographic Principle. Found a couple articles about it:

https://www.forbes.com/sites/startswithabang/2018/03/29/the-black-hole-information-paradox-stephen-hawkings-greatest-puzzle-is-still-unsolved/

Quote

The information, therefore, from whatever fell in would appear to be encoded on the surface area of the black hole itself.

&

 https://physics.stackexchange.com/questions/86391/how-many-bits-are-encoded-on-the-surface-of-the-smallest-black-hole (Didn't read this!)

 

3 hours ago, Strange said:

But it is still talking about the temperature at the event horizon.

You might be right. Gonna have to dig into that again soon.

Edited by QuantumT

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1 minute ago, QuantumT said:

I think it's a part of Susskind's Holographic Principle.

That just says that the maximum entropy of a black hole is proportional to the area (rather than the volume) of the black hole. It has nothing to do with the distribution of matter.

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3 minutes ago, Strange said:

That just says that the maximum entropy of a black hole is proportional to the area (rather than the volume) of the black hole. It has nothing to do with the distribution of matter.

I'm not gonna ague with that, because new unsupported ideas tend to be ridiculed here, but I'll just say that we have no inside data from black holes, only mathematical theories. Theories that I don't necessarily agree with (at least not all of them).

But to counter argue you have to show the math, and that's my achilles' heel, coz I am a bad mathematician (although I understand it perfectly).

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Black Holes have a temperature that is based on the fact that they have entropy.
This entropy is proportional to the area of the event horizon
The temperature is then manifested by radiation  ( at the equivalent black body temperature ).

The event horizon is the only external manifestation of Black Holes that we have, and although it is where all the physicality of the BH is manifested, it is not physical at all, but a mathematical construct.

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35 minutes ago, QuantumT said:

I'm not gonna ague with that, because new unsupported ideas tend to be ridiculed here,

Refuted isn't the same as ridiculed. 

37 minutes ago, QuantumT said:

but I'll just say that we have no inside data from black holes, 

Right, so you have nothing from which to make predictions and test them to see if they hold, so you can't say what the temperature is past the EH. 

39 minutes ago, QuantumT said:

only mathematical theories. Theories that I don't necessarily agree with (at least not all of them).

The math is a model, and theories are formed around the mathematical model. And theories are the ultimate in science, the highest achievement for any explanation. Mainstream theories are simply the explanations with a preponderance of supportive evidence, so I'm curious what it is you don't necessarily agree with. Which theories have evidence that's better?

42 minutes ago, QuantumT said:

But to counter argue you have to show the math, and that's my achilles' heel, coz I am a bad mathematician (although I understand it perfectly).

Sorry, but I don't buy this for a second. If you don't know the math, it's reasonably impossible to "understand it perfectly". Math is the language of physics, so your claim is like telling an Arab scholar you don't speak Farsi, but you understand it perfectly. Sorry again, but I call BS.

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2 minutes ago, Phi for All said:

Refuted isn't the same as ridiculed. 

Maybe not from your end. But from the other side it's a thin line.

5 minutes ago, Phi for All said:

Sorry, but I don't buy this for a second. If you don't know the math, it's reasonably impossible to "understand it perfectly". Math is the language of physics, so your claim is like telling an Arab scholar you don't speak Farsi, but you understand it perfectly. Sorry again, but I call BS.

I understand German perfectly. But if you ask me to speak it, it would take me ages to complete a conversation. Understanding is one thing, expressing is another.

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3 minutes ago, QuantumT said:

Maybe not from your end. But from the other side it's a thin line.

I'm not gonna ague with that, because new unsupported ideas tend to be ridiculed here,

Nonsense, new "unsupported" ideas are as you say, unsupported....Why would anyone entertain any unsupported idea, particularly when the proposer of that idea, is inevitably  claiming it as superior to an incumbent, well supported theory. 

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1 minute ago, beecee said:

Nonsense, new "unsupported" ideas are as you say, unsupported....Why would anyone entertain any unsupported idea, particularly when the proposer of that idea, is inevitably  claiming it as superior to an incumbent, well supported theory. 

I have never claimed anything I've suggested to be superior. If people do that, they ask to be ridiculed. So we can agree on that.

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13 minutes ago, QuantumT said:

Maybe not from your end. But from the other side it's a thin line.

Only if there's an emotional attachment to the idea, or the refutation is a personal attack rather than an attack on the idea. Correcting misconceptions and filling in gaps in our knowledge isn't ridiculous.

13 minutes ago, QuantumT said:

I understand German perfectly. But if you ask me to speak it, it would take me ages to complete a conversation. Understanding is one thing, expressing is another.

I don't believe you, sorry. You don't understand German "perfectly" if you can't speak it. My wife is fluent and there are still times she doesn't understand particular words and phrasing. Languages are too complex for the level of understanding you're suggesting. You are engaging in wishful thinking.

The symbols involved in mathematics are even more complex. I would consider your claim to understand them all perfectly to be ridiculous. Perhaps this is where you've gotten pushback in the past, not from discussing unsupported ideas. 

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15 minutes ago, Phi for All said:

I don't believe you, sorry. You don't understand German "perfectly" if you can't speak it. My wife is fluent and there are still times she doesn't understand particular words and phrasing. Languages are too complex for the level of understanding you're suggesting. You are engaging in wishful thinking.

The symbols involved in mathematics are even more complex. I would consider your claim to understand them all perfectly to be ridiculous. Perhaps this is where you've gotten pushback in the past, not from discussing theories. 

I will translate what you just said to german, and time it (no online help!):

Ich glaube dich nicht, must du verstehen. Du verstehst nicht deutch "perfect" wenn du das nicht sprächt. Mein frau kann es vollständig und manchmal kann sie nicht worte und ****. Sprache sind zu komplex für die *** des verstäehns das du ***. Du versucht wünchen zu denken.

Die symbolen involviert in des matematik sind serh viel mehr kompleks. Ich finde deine perfekte verstendness vonn dem vahnsin. Vieleicht davonn kommt deine früliger ***, und nicht vonn teorien diskutieren.

Time: 10:30 minutes. And some words I had to give up on. Many of the others are probably spelled wrong too.

I can watch a movie in german without problems, and understand it all. I understand the words when I hear them (in context). But finding the words when I need them is harder. It's because I have higher priorities - I think.

Edited by QuantumT

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Are we discussing Black Holes or the German language ?

The 'strictly science" forums are rarely, if ever ridiculed here.
Belief/opinion based forums such as religion/politics sometimes are.

( or when a poster develops an attachment to an idea bordering on faith, and cannot be convinced otherwise with facts )

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