Are black holes called black because nothing can ever escape from them, not even light

[Paulsrocket]

Or do black holes radiate Hawking radiation and, in the process, evaporate entirely yielding the information paradox.  Because both are written down and claimed as fact and the only real paradox is that both can't be true yet both are or were claimed as fact.  

[iNow]

They used to be called frozen stars, because light passing the event horizon around them appeared to freeze when viewed from another perspective. They also yes, do evaporate as per Hawkings calculations. 

As for the rest of your OP, the syntax is rather borked and hard to parse. 

These ideas are not considered as valid just because they're written down. They're accepted as valid because they accurate model the universe we encounter. 

[exchemist]

36 minutes ago, Paulsrocket said:

Or do black holes radiate Hawking radiation and, in the process, evaporate entirely yielding the information paradox.  Because both are written down and claimed as fact and the only real paradox is that both can't be true yet both are or were claimed as fact.  

My understanding is that Hawking radiation and its effects have yet to be observed. So while they are a mainstream theory, I’m not sure they have been claimed as facts. 
 

But in any event the two ideas are not incompatible if you understand them properly. Black hole is a term devised before QFT was applied to the phenomenon. So Hawking radiation phenomena can be taken to be a refinement of the earlier concept.

Edited January 4 by exchemist

[Phi for All]

!

Moderator Note

Just a reminder that Paulsrocket has reached their first day posting limit of five posts. Tomorrow the anti-spam measures will be dropped.

 

[MigL]

4 hours ago, Paulsrocket said:

and claimed as fact and the only real paradox is that both can't be true yet both are or were claimed as fact.  

No paradox; classical and quantum mechanics don't mix.
Black holes do not allow for the emission of anything, under classical considerations.

Black Holes do have entropy, however, and so, an associated temperature.
This temperature is barely above 0^oK, and since the universe is currently at 2.7^oK, BHs are actually net absorbers of mass/energy.
It is only in the far future, when the universe has cooled below a BH's temperature that it will experience net evaporation due to Hawking radiation.

Both Hawking radiation and the information paradox ( due to unitarity requirements ) are quantum mechanical considerations, and cannot be explained classically.

[swansont]

5 hours ago, exchemist said:

My understanding is that Hawking radiation and its effects have yet to be observed. So while they are a mainstream theory, I’m not sure they have been claimed as facts. 
 

But in any event the two ideas are not incompatible if you understand them properly. Black hole is a term devised before QFT was applied to the phenomenon. So Hawking radiation phenomena can be taken to be a refinement of the earlier concept.

Also note that the Hawking radiation, strictly speaking, doesn't come from the BH itself. The effect is initiated at the surface or just outside the BH. So both statements can be true. 

[Markus Hanke]

14 hours ago, exchemist said:

My understanding is that Hawking radiation and its effects have yet to be observed. So while they are a mainstream theory, I’m not sure they have been claimed as facts. 

This is true of course. It should be noted though that if both GR and QFT are valid theories, at least near the event horizon, then the existence of Hawking radiation is inevitable. If it turns out to not exist, then one or both of these models don’t apply in that region.

[J.C.MacSwell]

12 hours ago, MigL said:

No paradox; classical and quantum mechanics don't mix.
Black holes do not allow for the emission of anything, under classical considerations.

Black Holes do have entropy, however, and so, an associated temperature.
This temperature is barely above 0^oK, and since the universe is currently at 2.7^oK, BHs are actually net absorbers of mass/energy.
It is only in the far future, when the universe has cooled below a BH's temperature that it will experience net evaporation due to Hawking radiation.

Both Hawking radiation and the information paradox ( due to unitarity requirements ) are quantum mechanical considerations, and cannot be explained classically.

Theoretically a small enough BH, one about 0.75% of the mass of the Earth or smaller, should radiate above 2.7 and if not "fed" by more than the CMBR should evaporate and disappear.

[Paulsrocket]

10 hours ago, J.C.MacSwell said:

Theoretically a small enough BH, one about 0.75% of the mass of the Earth or smaller, should radiate above 2.7 and if not "fed" by more than the CMBR should evaporate and disappear.

2 + 2 = 4, no theory involved as this is easily proven.  So math is never theory, it either works or it fails which makes it wrong not a theory which is why dark matter was invented as without the missing mass the math fails, and the universe can't be proven.  As for black holes they once claimed that nothing could escape, now they say different, Hawking clearly admitted what he believed was his mistake, Einstein made a similar mistake that Hubble forced him to admit as well.  Sorry for mixing ideas but it's all related and part of the same Universal enigma.  

[zapatos]

9 minutes ago, Paulsrocket said:

Universal enigma

Sorry I missed it, but what is the "Universal enigma" you are talking about?

[Phi for All]

59 minutes ago, Paulsrocket said:

2 + 2 = 4, no theory involved as this is easily proven.  So math is never theory, it either works or it fails which makes it wrong not a theory

Maths are used to model theories. The Lambda Cold Dark Matter model supports the Big Bang Theory, for instance.

1 hour ago, Paulsrocket said:

which is why dark matter was invented as without the missing mass the math fails, and the universe can't be proven. 

You're mixing standards here. Proofs are for maths (and formal logic). Theories are NEVER "proven", no explanation for anything in the universe is "proven". Theory is our best supported explanations, and the methodology works best if we always assume there's a better (or more detailed) explanation. When you think you've found an answer, you stop asking the question, so theory keeps us searching for better and better evidence for our explanations. Does that make sense to you?

1 hour ago, Paulsrocket said:

As for black holes they once claimed that nothing could escape, now they say different, 

No, you didn't read what swansont said. Hawking radiation happens just outside the event horizon. Nothing is entering and then finding enough energy to leave.

 

[exchemist]

2 hours ago, Paulsrocket said:

2 + 2 = 4, no theory involved as this is easily proven.  So math is never theory, it either works or it fails which makes it wrong not a theory which is why dark matter was invented as without the missing mass the math fails, and the universe can't be proven.  As for black holes they once claimed that nothing could escape, now they say different, Hawking clearly admitted what he believed was his mistake, Einstein made a similar mistake that Hubble forced him to admit as well.  Sorry for mixing ideas but it's all related and part of the same Universal enigma.  

You have not taken in what we have been explaining to you, apparently. Classically, nothing can escape, that was the original conception of the black hole and is still strictly true of them. Later however, Hawking applied QFT to it and showed that the region at the rim, but just outside, would be caused to radiate by the intensity of the gravitational effect it creates. There is no inconsistency here and no "mistake" to be admitted. Nothing that enters can leave. That remains the case. But radiation just outside can certainly do so and this may make them look less "black" to an observer than in the original, non-QFT, conception of them.   

Do you understand?  

  

[MigL]

19 hours ago, J.C.MacSwell said:

Theoretically a small enough BH, one about 0.75% of the mass of the Earth or smaller, should radiate above 2.7

True.
But we know of no mechanism for producing such Black Holes.
Stellar gravitational collapse produces BHs that are an order of magnitude more massive than our Sun; and they are much colder than the CMB.

Extremely small BHs of the size you mention, could only have been produced by primordial density fluctuations of the hot dense plasma of the very early universe, and they would have, and be, evaporating.
Yet we look around the universe, and back in time, and we don't see the tell-tale gamma ray bursts indicative of the final moments of these primordial BHs.
There may just not be any.

[J.C.MacSwell]

2 hours ago, MigL said:

True.
But we know of no mechanism for producing such Black Holes.
Stellar gravitational collapse produces BHs that are an order of magnitude more massive than our Sun; and they are much colder than the CMB.

Extremely small BHs of the size you mention, could only have been produced by primordial density fluctuations of the hot dense plasma of the very early universe, and they would have, and be, evaporating.
Yet we look around the universe, and back in time, and we don't see the tell-tale gamma ray bursts indicative of the final moments of these primordial BHs.
There may just not be any.

I guess that means that with regard to black holes "there's nothing new under the Sun" 😄

[Paulsrocket]

On 1/5/2024 at 2:51 PM, zapatos said:

Sorry I missed it, but what is the "Universal enigma" you are talking about?

The universe can't be proved mathematically and as such it is being referred to as a simulation by some at this point because the quantum and macro realms fail to unite 

[Markus Hanke]

2 hours ago, Paulsrocket said:

The universe can't be proved mathematically

What do you mean by this, exactly? The universe is just there - all we do in physics is to find models that provide the best possible descriptions of aspects of it. 

2 hours ago, Paulsrocket said:

because the quantum and macro realms fail to unite

Most of it “unites” just fine, it’s only gravity that is a problem right now. But we’re working on this - physics, like any other science, is a process.

[Paulsrocket]

4 hours ago, Markus Hanke said:

What do you mean by this, exactly? The universe is just there - all we do in physics is to find models that provide the best possible descriptions of aspects of it. 

Most of it “unites” just fine, it’s only gravity that is a problem right now. But we’re working on this - physics, like any other science, is a process.

How is it that you do not know that 85% of the mass and energy for gravity to exist as a universal force is missing and as such unseen possibly nonexistent dark matter was invented to balance the gravitational equations.  I chose the term enigma for this.  What do you call the missing 85% of the universe?  

[joigus]

On 1/5/2024 at 8:41 PM, Paulsrocket said:

2 + 2 = 4, no theory involved as this is easily proven.  So math is never theory, it either works or it fails which makes it wrong not a theory which is why dark matter was invented as without the missing mass the math fails, and the universe can't be proven.  As for black holes they once claimed that nothing could escape, now they say different, Hawking clearly admitted what he believed was his mistake, Einstein made a similar mistake that Hubble forced him to admit as well.  Sorry for mixing ideas but it's all related and part of the same Universal enigma.  

Apparently you can't be bothered to read other people's answers. Also, what on earth does DM have to do with BH?

[Paulsrocket]

37 minutes ago, joigus said:

Apparently you can't be bothered to read other people's answers. Also, what on earth does DM have to do with BH?

Which human has the answer as to where dark matter is and as such can complete the gravitational equations scaled up to the universe?  He or she who uncovers this will win a Nobel prize.  Black holes contain mass and energy, the Earth is in orbit around one as is our Sun

Edited January 8 by Paulsrocket

[joigus]

18 minutes ago, Paulsrocket said:

Which human has the answer as to where dark matter is and as such can complete the gravitational equations scaled up to the universe?  He or she who uncovers this will win a Nobel prize.  Black holes contain mass and energy, the Earth is in orbit around one as is our Sun

It's the "what" that's a problem, not the "where". And the equations don't suffer any essential modification. It's just another source term on the right-hand side of the Einstein field equations.

Another matter (never mind pun intended) is what DM is. And we're drifting off topic.

[Markus Hanke]

1 hour ago, Paulsrocket said:

What do you call the missing 85% of the universe?  

I call them by their usual names, Dark Matter and Dark Energy. Had you clearly stated that this is what you were referring to, your posts would have been easier to decipher.

Nonetheless, the answer is the same as with the quantum gravity issue - right now we’re not sure about the precise nature of these entities, but it’s being worked on. Such things take time and effort to understand. Perhaps also the answer might be a modification of the laws of gravity (also being worked on); though, considering latest results, the air seems to be getting a bit thin for that option.

Like I said, science is an ongoing process.

Edited January 8 by Markus Hanke

[Paulsrocket]

1 hour ago, joigus said:

It's the "what" that's a problem, not the "where". And the equations don't suffer any essential modification. It's just another source term on the right-hand side of the Einstein field equations.

Another matter (never mind pun intended) is what DM is. And we're drifting off topic.

Then you can tell us where dark matter is.  Nope you can't do that, because the moment dark matter is located it ceases to be dark.  This is the enigma

Edited January 8 by Paulsrocket

[exchemist]

33 minutes ago, Paulsrocket said:

Then you can tell us where dark matter is.  Nope you can't do that, because the moment dark matter is located it ceases to be dark.  This is the enigma

Not true. We know dark matter is in galaxies, because it is the deviation in their rotation rates from what would be expected from the masses of the bright matter they contain (which we can estimate)that leads us to infer there is extra "dark" matter present.  

[joigus]

47 minutes ago, Paulsrocket said:

Then you can tell us where dark matter is.  Nope you can't do that, because the moment dark matter is located it ceases to be dark.  This is the enigma

As said by exchemist and myself, we do know where it is. Deviations of the velocities of galaxies and application of the virial theorem allows us to do so. A different question is what it's made of: black holes, neutrinos, other particles allowed by natural extensions of the standard model?

Several members --and I'm one of them-- seem to be of the same opinion. Namely; that you don't know very well what it is that you want to talk about (is is BH's, DM, DE?); and that everything is the same "enigma" for you, your umbrella term for every unknown.

You are either deluded or confused, or perhaps unwilling to understand the current status of the theory of cosmology. Pretty much everyone knows by now that you are, and it only remains to be seen whether or not you are willing to take some information in. If you are, some people here could be of much help.

[Phi for All]

1 hour ago, joigus said:

You are either deluded or confused, or perhaps unwilling to understand the current status of the theory of cosmology. Pretty much everyone knows by now that you are, and it only remains to be seen whether or not you are willing to take some information in. If you are, some people here could be of much help.

It just occurred to me that this could be a procrastinatory practice. You know you have a huge mountain to climb, so you start looking for reasons not to start; looks like rain, need new shoelaces, is this the best route? 

Lots of science to study. Looks like some discrepancies, need new books, is this really true? Much easier to blow it all off as not worth it because of all the enigmas. Saves a LOT of time.